Sunday, July 24, 2011

The magic carburator

If you are around in the car culture long enough you will eventually hear about some old crusty guy who invented a carburetor. There are some of you who probably know where this is going and for others this may be the first time you hear this. This story is complete BS and I will explain why.

The Story
The story always follows this pattern:
Some guy tells you a friend's relative (or distant relative's friend) was working on some big pig old (Cadillac, Lincoln, Buick, Mercury, Chrysler, or some other land yacht), and came up with a new carburetor design in the (40's, 50's, 60's, or 70's). It was so good he drove this vehicle (half way or the whole way) across the country and used only (a half, a quarter, an eighth, or a whole) tank of gas doing so. Upon returning home he shopped the design of this carburetor around to (GM, Ford, Chrysler) and they were very interested. A few days later (the government, Arab sheiks, auto executives, oil executives) showed up and (killed him, paid him millions, disappeared him) taking his new carburetor. Currently the (oil companies, government, car companies, oil cartels, or any combination of them) are sitting on technology that could easily give up (100, 200, 300, 500, or 1000) MPG in our current cars.

The Truth
Personally I am sick of hearing this story. I don't know if people actually believe this story, like telling it because they are into conspiracy theories, or like messing with people who don't know much about cars. Very often the story teller will mention a specific type of carburetor, a fish carburetor, a catalytic carburetor, or a vapor carburetor. Basically it is impossible to create a vehicle of that size that gets that type of mileage. My other thought is that people are confusing the ultra high mileage cars that various teams build with actual cars. Now the ultra high mileage cars take fuel savings to new levels and basically these contests are about who can abuse the rules the most. These things are slow, extremely  light, seat one, and are started by pull sting. To achieve these extreme mileages the teams go and find about the smallest girl they can to have as the driver and then build the car body around them. Depending on the class that these cars a competing in they typically get between 500 and 3000 mpg.

Now if you are going to hold those types of "cars" up as proof that we can build cars that get extreme gas mileage and Detroit, the Government, or the oil companies are just withholding this technology they you are kidding your self. To improve on fuel economy there are only about 4 things that you can do and most you can't change once you purchase the vehicle.

Engine efficiency
This is one of the things you can change some on an existing vehicle. Internal combustion engines are typically between 20% and 30% efficient meaning that they only extract between 20% and 30% of the energy of the fuel. Now for those of you who think that this is some massive conspiracy and that they should be closer to 100% then you are kidding you self. The internal combustion engine that has the highest efficiency is a combined cycle GE gas turbine that is about 60% efficient and is used in power plants. For reciprocating piston engines the best is about 50% and that is only achievable in large engines like this one with a bore of 3 feet and a stroke of 8 feet. For those of you who think someday we might actually achieve 100% efficiency you are kidding your self. Thermo dynamics puts a limit on the maximum efficiency that can be achieved, this limit is the carnot cycle efficiency. So lets assume that it is possible to have a 100% what would one of those big pig cars mentioned earlier get. Well if we assume currently one of those engines is 20% efficient (this number will help our calculation) and lets also assume that the vehicle gets 20mpg (a gross overstatement, but it makes the numbers work out nicely they probably got more int he range of 12-14mpg) then by putting a 100% efficient engine in it it would get 100mpg which is pretty good but is would be a gross overestimate for this car which is frequently used in the story.

Mileage through lightness
Another way to get good mileage is to have a lighter vehicle. Those high mileage competition vehicles weight int eh 100-200 pound category, sometimes weighing under 200 pounds with driver. You can make some changes to your vehicles weight but don't expect any significant ones unless you start taking out everything you don't need including seats, and other trim pieces. Even then your vehicle will still weigh significantly more than those mileage competition cars, hell most motorcycles weigh more than those cars. The cars in the story usually weight in between 5,000 and 8,000 pounds or between 25 and 40 times the weight of the high mileage competition cars.

Better Aerodynamics
This is something you really can't change on your vehicle for the better, but you can make worse. If you look at those high mileage competition cars they are extremely aerodynamic. They also present a very small cross sectional area which also has a lot to do with how much energy is needed to move the air out of the way. Now compare that to another favorite car in the story and you can see how bogus thing really are starting to become.

Go slower
One thing all of those high mileage competition cars have in common is they are slow. Typically they will start the engine get up to speed and then shut it off and coast to a stop then repeat. These cars would be fast if they could go 30 mph. At these slow speeds you have less wind resistance. Now compare that to any production car made in the last 60 years. For the most part all cars made after WWII can reach 100 mph some can even go well over 200 mph.

So what gets really good mileage
Even today's best production cars don't get as good of milage as the best ones of all time. If you want to maximize your fuel economy I suggest reading this posting of mine but don't expect incredible gains at best you might get 5 or 6 mpg extra. The problem is most people don't want the cars that get close to 100mpg as they seat one maybe 2 don't have much power, and aren't very safe. If you are curious about these cars here is a list of some of the more famous or unique ones:

Tuesday, July 19, 2011

Beat the heat

With some really oppressive heat and humidity over us here in the mid west (I know those of you down south get it worse) I have noticed a number of vehicles broken down on the side of the road. This kind of heat is just as hard on your vehicle as the bitter cold (sorry for those of you down south you can't even compete on that one). So how do you keep your vehicle running well in this kind of weather.

If you haven't changed it recently you might want to consider doing so. A good flush and fill will go along way to ensuring that your car will stay cool and continue running. Also if you haven't checked your coolant level recently do so and fill as necessary as you will want the maximum amount of cooling capacity. If you have a vehicle that has been modified to produce more power you factory cooling system my not be able to keep up. A little trick to ensure that these vehicles stay cool is instead of using the standard 50/50 mix of antifreeze and water is to run almost 100% pure water with a product like Water Wetter to lubricate the pump (also it decreases the surface tension in the water allowing for more cooling). Granted this mix doesn't have as high of a boil over protection, but will keep your engine running much cooler since 100% water has a much better thermal transfer than a 50/50 mix of water and antifreeze.

If yours isn't working as well as it use to you may just need a new cabin air filter. Changing these is similar in difficulty to changing the engine air filter but a little more expensive with the filter costing $10 to $15. If this still doesn't help you may be low in refrigerant in the AC system. Unless you know what you are doing I suggest you  take your vehicle to a professional as it is pretty easy to over fill the system and then wreck seals thus making your poorly working AC into a non working AC

Tires should always be properly inflated, especially in hot weather. Too little air and your tire will over heat and you will be suffering a blow out and have to change a tire in this crappy weather. Too much air and your tire may just burst and you will be stuck changing a tire in this crappy weather.

Heat kills batteries so if you have a battery that is old and questionable you might want to change it out before you get stuck. Also keep your battery properly charged will go along way to preventing the stresses that can prematurely kill a battery.

In addition to providing lubrication to your engine oil also helps cool it as it flows. In extreme heat you should ensure that you have the proper amount of oil so as to maximize the cooling capacity. Additionally using a synthetic oil will decrease the internal friction thus helping your engine stay cool.

If you have the opportunity to park in the shade or in a covered ramp I suggest doing so. Not only will this keep the interior of your car from becoming an oven, but it will help protect interior trim and the pain. Heat is what causes the plastic in things like dashes to dry out and crack. Also by keeping your vehicle out of the sun it helps protect the paint from UV damage thus helping the paint prevent your car from rust. If you can't park in a shaded area I highly suggest getting one of those windshield shades and cracking your side windows to keep the interior heat down.

Sunday, July 17, 2011

Don't expect a miracle in a can

If you have been in an auto parts store, down an auto care isle, or watched infomercials then you have seen them. These are the miracle in a can products that promise to do almost magical things to your engine. There are some that claim they will make your engine last for ever, be cleaner, stop leaks, get better gas mileage and so on. The truth is these products produce varied results some work great while others do nothing to fix the problem. Most of the problems these products attempt to resolve could have been prevented by doing regular maintenance on your vehicle.

Stop Leak Products
These are probably the most common types of products out there within this group there are products that stop coolant leaks, oil leaks, and I would also include ones that stop burning of oil.With the various stop leak products you actually have a decent chance of them working. The bad news is that any fixes they provide are temporary at best. Oil stop leak products work by either "reconditioning" seals and gaskets or by thickening the oil so it doesn't leak out (this is also how the products that stop your car from burning oil work). With ones that recondition seals and gaskets all they do is cause the gaskets to swell so that the gasket plugs the gap, void, or crack. These will work for a while but eventually you will have a leak again. The only real fix is to replace the gasket or seal that is leaking. The products that thicken the oil I am not a big fan of as they really don't fix anything but just mask the problem. Add to that these products thicken oil I start to question if they are really good for your vehicle since you vehicle was designed to run with a specific weight of oil. As far a coolant stop leak products, I have had varied success with these, some of them seem to work some of them don't. Basically if you have a leak on a non moving part of your coolant system (i.e. not the water pump) then this product will plug the hole. I don't know how permanent these fixes are but once I have gotten home I go do a proper fix (solder, weld, or replace) so that I don't have to worry about the stop leak product.

Clean mechanical parts inside your car
These are also very common products and provide varying results. There are products to clean your fuel system, combustion chamber, engine, transmission, cooling system and so on. Basically these products are solvents. The ones that are put into the gas tank are meant to do one or more of the following:

  1. Remove deposits from the fuel system. This usually called fuel deposits and are basically varnish. This can happen over time if you let vehicles sit for a while, the vehicle doesn't consume much fuel, or has a lot of miles on it. This also includes products like fuel injector cleaner or carburetor cleaner. Here I think that some products work better than others, but generally they won't cause any damage if used.
  2. Remove water from the fuel. Products that do this usually have alcohol in them as alcohol will absorb the water and will still blend with gas. Getting water in your tank can happen if you have an old vehicle who's tank doesn't seal well, or if you bought some bad gas. These products were more common years ago, but now with most gasoline already having ethanol in it the need to remove water is lessened. These products usually work well as they solve only one problem that is pretty simple to fix.
  3. Oil additives to clean out deposits in the engine. Personally I don't like these products as they thin the oil. This will decrease the ability of the oil to properly lubricate. I have used the products in the past but when I do I only use them just before an oil change and then only drive for a little bit with them. I only do it the first time I change oil on a vehicle because most people don't change their oil as frequently as they should and this will remove the deposits and sludge that have built up. If you change oil when you should this is something that never needs to be done. Using these products on a very neglected engine may actually make things worse as those deposits may have been plugging leaks or filling voids so now your vehicle may leak oil or burn it so it is best to just take care of your stuff to begin with than hope for a miracle fix in a can.
  4. Coolant system cleaners. My feeling with these is similar to that of oil additives, they may work, but you would be better off taking care of the system to begin with than using one of these products and hoping for a miracle. Usually issues these products resolve are silted up cooling systems, rust, and calcium build up. These problems can all be avoided by doing a flush and fill on your coolant regularly. Also as with oil additives using one of these products may reveal other problems as they clean away the neglect. 
Performance improvements in a can
Unless you are running an extremely high compression engine or using a lot of boos don't expect much of anything from these products. The reason is that mostly these are placebo products. The only ones that do anything are those that increase the octane of the gas you are running, or in the case of diesels increase the cetane number. Increasing the octane doesn't do anything unless you have an engine designed for higher octane (even higher than the 91 or 92 premium fuel) than can normally be found. Unless you have modified your engine substantially (made a race engine out of it) you don't need these. Also don't expect any product to magically increase your fuel economy. If you use one of these products and your car magically starts running better it probably is because something is wrong with your car that needs to be fixed. It will be cheaper in the long run to actually fix the problem instead of keeping buying stuff in the can.

So what products do I like
There are some gems out there for the products in a can. Below is a list of products I like and have had success with in the past.

Oil stop leak - If you really want to use a product to stop oil leaks and not just replace gaskets or seals then go use something like Valvoline Max Life or Mobile 1 High Mileage. I would recommend either of these since you aren't playing backyard petrochemist. These are designed to meet the correct specifications of the oil for your vehicle instead of you just dumping stuff in. Don't expect results overnight with these products as it takes time for them to cause the seals and gaskets to swell and plug the gaps or cracks.

Coolant stop leak - I have had success in the past using the Bar's Leaks Lquid Aluminum product. When using products like this you need to drive the vehicle around for a while. This prevents it from solidifying into a big clump in the overflow tank. As I have mentioned I use this as a temporary fix and when I get home I go and do a real fix. 

Fuel system cleaners - Lots of people swear by Chevron Techron, but personally I like the Berryman B-12 Chemtool fuel system cleaner or injector cleaner. Basically these are some of the most caustic things I have ever used. I was introduced to them when cleaning the intake manifold on my car and had gone through several cans of regular carb cleaner and the guys at the auto parts store suggest the spray form. It really does clean well, don't get it on your paint, or on your hands. Also recently I have seen a couple of gas stations advertising the they carry gas to meets or exceeds top tier gas standards. I would say using these fuels would be a better option as again you aren't playing back yard petrochemist. Both Holiday and Kwik Trip in my area have recently started offering these. 

Oil additives for cleaning - I have used Seafoam to do this I put in the recommended amount and drive for a max of 30 miles and then change oil. I don't regularly use this since changing your oil at the correct time is the better option. As a side not Seafoam works great for fogging motors when putting them away for the season.

Coolent system cleaners - None, just do regular flush and fills.

Performance in a can - None, but if you really feel you need to run high octane fuel you can always go and get some leaded avgas down at the nearest airport for about $6 a gallon or race track for about $8 a gallon. If you feel you still need more octane then you are doing something wrong. 

Sunday, July 10, 2011

Minimize the cost per mile driven

With fuel prices rising again, oil is back near $100 a barrel, you will probably want to minimize your cost of driving. Some helpful hints are common ones, but others are some lesser know things. One thing I have discovered in my years of working with cars and being around the car culture is that there are similarities between vehicles that get really good mileage and high performance vehicles.

1. Proper tire pressure
Keep your tires properly inflated. This will help decrease the rolling resistance (friction between your tires and the road) increasing fuel mileage. The higher tire pressure you have the lower rolling resistance between them and the road. While it may sound good to just crank the pressure way up this isn't a good thing either as it will affect the ride quality, tire wear, and safety.

2. Clean your car out
Not only will your friends want to ride in your car you can cut your fuel consumption. Granted in most cases this won't amount to much if any but if you carry around a bunch of junk (10's to hundreds of pounds) there might be a noticeable difference.

3. Keep your vehicle tuned
By keeping your vehicle properly maintained you can keep it running as efficiently as possible. See my previous posting on a vehicle maintenance schedule. Not only will this schedule keep your car running for a long time it will keep it running optimally.

4. Fuel saving tires
Fuel saving tires can help reduce your fuel consumption as they offer lower rolling resistance between your tires and the road.

5. Decrease drag
Remove external accessories for your vehicle. Just as cleaning out the junk can increase fuel economy so can removing unneeded exterior accessories. Typically this will be things like roof racks, bike racks, hitch accessories. Not only are you decreasing the weight of your vehicle, but you are decreasing the amount of drag caused by the wind hitting these things.

6. Use the correct gas
People seem to think that using premium gas will increase their fuel economy, the truth is if your vehicle is running correctly it won't. The truth is your vehicle was designed to run on gasoline with a specific octane (typically 87, 89, or 91). Granted using a higher octane won't hurt your car, but it does cost more money. By running a lower octane fuel in your car than recommended in you will waste fuel. This is because modern cars can compensate for too low of an octane by dumping more fuel in. This will prevent preignition, but will cause your car to run rich and will shorten the life of O2 sensors and catalytic converters. The truth is gasoline regardless of octane contains the same amount of energy.

7. Use synthetic fluids
Synthetic fluids can help increase your fuel economy. Granted they are more expensive, but they last longer. I cover synthetic oils in detail in this post. In my daily driver I run synthetic oil in the engine, synthetic transmission fluid in the transmission, and synthetic gear oil in the read differential. Most of the benefits of synthetic fluids come from the superior lubrication, decreased friction, and better flow, it takes less energy to move them around.

8. Use lighter oil
You can get better fuel economy by using a lighter oil. In my daily driver I run 0w30 in the cold Minnesota winter and then work up to 10w40 in the summer using either 5w30 or 10w30 in the spring and fall depending on temperature. As temperatures warm you shooed be using heavier oils to protect your engine, but don't use a heavier oil than necessary.

9. Gas coupons
Not all states allow or have gas coupons but I know here in Minnesota several gas station chains have gas coupons. Both Kwik Trip and Holiday station stores have gas coupons in the St. Paul paper for up to 7 cents off a gallon. The Kwik Trip coupons are in the St. Paul paper on the first Wednesday of the month, and the holiday coupons are in the St. Paul paper on the last Wednesday of the month. Additionally you can sometimes find gas coupons online for gas stations like Holiday Station stores have.

10. If your car takes 89 octane some stations sell it at the price of 87 octane
If you are unlucky like me to have a car that takes the mid grade (89 octane) you are kind of stuck paying a higher price per gallon for gas unless you know what gas stations sell the mid grade (89 octane) at the same price as regular (87 octane). This can save between 7 and 12 cents a gallon. I know that the Kwik Trip stores near me do this as do a number of the Holiday gas stations.

11. Use gas that doesn't have ethanol in it
In Minnesota this is basically impossible, yes you can buy non-oxy fuel but it is few and far between, but I believe that some states still sell gas without ethanol. If you are in a state that has a 10% ethanol mandate you loose about 3-4% of your mileage because of the lower energy content of ethanol.

12. Leave some distance between you and the one in front of you
Now it is theoretically possible to get better mileage by following closely behind another one. This is because of decreased drag, but is also dangerous and rarely produces good results. The reason for this is that you are varying your speed more than you normally would. By leaving more space between you and the vehicle in front of you 12. Leave some distance between you and the one in front of you you may not have to overcome more wind resistance, but you will be able to drive at a more constant speed. Also in rush hour traffic you can gradually slow down and speed up when doing this. Quick starts and stops really wreck mileage.

For the most part I practice what I preach and doing these things can lead to significant gains in mileage. My daily driver is an 1997 BMW 540i with a 5 speed automatic transmission, sport package, and has 215,XXX miles on it. This vehicle was claimed by the government to get 18 MPG combined and qualified as a cash for clunkers vehicle, I have never gotten that poor of gas mileage. My rolling average over the last 114,000 miles or so (I got the vehicle with 101,000 miles on it) has been 22.7 MPG according to the on board computer. This is more or less what I see when I fill up but is definitely in the correct range. I drive 32 miles one way (64 round trip) to work each day in rush hour traffic plus all the other little BS trips I make in a week. The best mileage I have ever gotten has been on long trips that are mostly open road. Typically on trips these I get in the 27 to 29 MPG range and have gotten that several times, most recently was last weekend going up to the iron range and back averaging 28.2 MPG round trip on a trip that was just a little over 400 miles. I could probably get better mileage but I do like to drive in a rather um "spirited" fashion especially on freeway entrance and exit ramps.

Friday, July 8, 2011

Tricks for a failed starter

If you own an older vehicle you will eventually have a starter fail, usually when you really need to go somewhere. I have had starters fail on several vehicles and have still been able to drive them to the auto parts store to get a new one.  There are really 4 ways of starting a vehicle that has a bad starter but each method is applicable in specific circumstances. These methods are not guaranteed to succeed, and if they do you are on borrowed time so get a new starter as soon as possible.

1. The Hammer
This method can work of the starter solenoid is sticking. You can tell this if when you turn the key you hear a click but nothing else (no normal starting noise) , but have a good battery. Go get your self a stick, hammer, tire iron, large screwdriver, or any other long object that you can whack the starter with. Don't hit it as hard as you can as this my break your starter, but start off fairly light, it shouldn't leave a mark on the old starter, then try to start it. If it doesn't work give it another slightly harder whack and repeat. If after a few tries it still doesn't start you will need to replace the starter.

2. Jiggle the car
This method can work if you have a worn gear on the starter. You can tell this if when you try to start the car you hear a high speed motor spinning. It sounds similar, but quieter, to a vacuum cleaner. This noise is the starter motor not catching the gear on the outer edge of the flywheel on the engine. Put the car in gear and try to move it back and forth a couple of times. This may move the gear on the flywheel enough so that the starter can grab it now and start the car.

3. Hot wire it
This method can work if your solenoid has completely failed, you don't even hear the click mentioned in number 1, or you have bad wiring going to the solenoid or starter. It is easiest on vehicles that have the solenoid separate from the starter but might be possible on vehicles with the starter and solenoid all in one. Here you will need to turn the key to the run position and then create a short across the terminals of the solenoid. If you have an external solenoid this is easier as you can see what needs to be shorted, it will be the terminals with the really big wires connected. I suggest using a large plastic handled screwdriver for this as they can carry the very large current and you won't electrocute yourself.

4. Pop start it
If none of the above methods work and you have a vehicle with a manual transmission this will work, provided you can get the car rolling fast enough. Again first you will turn the key to the run position. Then put the vehicle in neutral.  Next you will either need to get out and push the vehicle, or let it roll down a hill. When the vehicle is going near 5 mph get back in, close the door, put it in gear and let the clutch out and be ready to give it some gas. If it doesn't start you will have to try again, I suggest getting it going faster. The only time this hasn't worked for me on a manual transmission vehicle when when I had to push it up a hill.

These tricks may not work every time but I have used all of them in the past with success. When you do finally get your vehicle running remember you are on borrowed time and need to replace your starter, so I suggest driving to the auto parts store leaving your vehicle running and getting a new starter as you may not be able to start it once turned off. If none of these are an option then you will be stuck either paying for a tow or borrowing a vehicle to get a new starter.

Friday, July 1, 2011

Your check engine light is trying to tell you somethign

One thing that seems certain in older vehicles is that you will see the check engine light. I have seen a lot of people ignore this light as their cars appears to run as good as it ever has but truth is something is wrong. In most cases the check engine light is indicating some emissions related issue or a misfire, other times it could be indicating something much worse. The check engine light indicates that your engine is not running optimally and what ever is causing this should be addressed. Even worse is when your check engine light is flashing, you shouldn't be driving your car when this happens.

To find out the cause of the check engine light being on you will need a scan tool. If you don't own one that is fine as a number of auto parts stores loan them out, or will even do the scan for you. For more information on scan tools see this post of mine. Once you have the code (they have the form of P####, B####, or C####) you will need to figure out what it means. Some scan tools will tell you, but if the one you are using doesn't then you can find out what it means by:
  •  Looking it up in a repair manual for your car
  • Asking the clerk at the auto parts store
  • Looking it up online
If you are going to look it up online I suggest going to this site, or directly putting the code into a search engine like Google and including the make and model of your vehicle as well.You probably aren't the first person to have this problem with your vehicle so by searching for the error code and you make and model you can find out what others did to resolve the problem.

I do like asking the auto parts store clerks as they usually are knowledgeable and if you used their scan tool then you are there already. Sometimes they can provide a detailed printout of what the error code means which is even more helpful. Also you will probably need to purchase a new part anyway which is why the auto parts store lets people use the scan tool for free.

In my experience most codes are caused by old spark plugs (misfire), old O2 sensors (slow sensor, bad reading for a sensor, failed sensor), old spark plug wires or boots (misfire), or some failed sensor (throws a sensor failed code). The good news is that a lot of these issues can be avoided by following a maintenance schedule and replacing these parts before they cause a problem.

Finally in closing let me say that it is always a good idea to solve vehicle issues right away. The check engine light looks the same if you have one error code or 50, and with it on your vehicle is not running as well as it should and may be wasting fuel, polluting, or wrecking other parts without your knowledge.