Question: Why do race cars run on different fuels?

All forms of motorsport have rules and regulations put together to create an atmosphere of fair competition. Since we are dealing with complicated mechanical devices, there will never be 100% equality in racing vehicles, but the higher the level of legislation, presumably the closer the contest or at least the emphasis is supposed to shift more towards the drivers abilities. One of the areas that is often specified in these regulations is fuel.We know from the earlier discussion that the design of the engine and the type of fuel are closely tied so it stands to reason that if you spec the fuel there should be only so much you can do to the engine because of the limit of performance that the fuel type will allow. If a competitor is running on "illegal" fuel it won't necessarily help him go faster but the fact that the fuel doesn't comply may be an indication of other undetectable technical enhancements. Finding illegal fuel usually means instant disqualification and they don't have to find out if there are other noncompliance's to take advantage of the fuel. So the short answer is that race cars will run different fuels because of a specification in the rules.

Of course there are exceptions: races like the Pikes Peak Hill Climb, which is one of if not the oldest continual running events in the world. A race up a winding road around a mountain, where the vehicles have to be able to operate over a difference of several thousand feet of altitude. Its not and easy thing to do and there are many different ways to skin this cat. Here the big limiting factor is the constantly changing conditions of the road and atmosphere on the way up the mountain, so fuel is open. They even run Natural Gas cars here quite successfully. There are a number of different classes of vehicle based on weight and size and on how many wheels are driving etc. But on the unlimited class, it is truly a “run what you brung” scenario.Every thing so far that we have talked about has been mainly gasoline and additives in it to modify the octane as mentioned at pikes peak, not all race cars run on gasoline or at least gasoline as we know it. The formula one guys use what they call gasoline but this petroleum cocktail probably costs more per liter than an entire fill up in the average “grocery getter” and you probably wouldn't want to spill any on your self. But some cars run entirely on another fluid. Methanol is the only fuel that the Indy car will drink. As we said before, the internals of the engine have a lot to do with the fuel it burns and this is true in spades here. The pure methol alcohol is highly corrosive to some metals. It can turn aluminum into a white powdery mess that resembles baking soda in very short order. Plus it mixes very well with water so anything steel will rust overnight. The internals of the entire fuel system has to be Teflon and stainless steel and even the fuel bladder in the car has to be made from a special compound, the valve seats have to be brass. The corrosion problem means that none is left in the engine overnight -- even the cylinder walls if steel, have to be fogged with oil so they won't rust for even the shortest of storage time. Sounds like pretty bad stuff with a lot of negatives. Oh yeah, I almost forgot it only has about half the heat energy of gasoline so a regular race car that would get 4 miles to the gallon of gas goes only 2 miles on methanol that's not quite a full lap of the Indianapolis Race Track of 2.5 miles.  So why even consider this stuff as a race fuel? Well remember the octane thing and its tie to performance, well methanol has an incredibly high natural octane in its pure form. The average street car might have a compression ratio of about 9:1 -- well you can more than double that in a methanol burning engine, which makes it especially good for engines with the compression ratio artificially boosted with a super charger or turbo charger. Indy car engines run a compression ratio of about 16:1 with a turbo this makes a fairly good recipe for about 800 hp out of 2.6 liters of cylinder displacement. Back in 1970's Indy cars typically used an Offenhauser 4 cylinder engine with unlimited boost and were making over a thousand hp. But as the cars overall sophistication increased, so did the speeds. So limiting the boost level here became the limiting factor for this sanctioning body.

But funny enough, power potential is not why "all" Indy cars run methanol. The Indianapolis motor speedway in Speedway, Indiana, a suburb of Indianapolis, was constructed by the ancestor of the present owner as a test track for all auto manufacturers around the world to prove their product to the public. At this time in history the center for automotive industry in the USA was the Midwest, Manufactures like Cord, Deusenburg and Dodge, Cheverolet, Auburn, just to name a few, all were located in the surrounding area. But car manufactures like Alfa and other Europeans also came to compete at various times throughout history. Anyway just like Pikes Peak any type of fuel was OK. It was up to the car builder to figure out the winning combination. The diesel manufacturer Cummins qualified on pole with a diesel and led the majority of the race until a small non-fuel related problem retired the car just minutes from the finish. The Parnelli Jones Turbine powered car did virtually the same thing as the diesel retiring late in the race with a bearing problem, again not related to the fuel. There was even a plan by the Late Bill Lear, inventor or the 8 track tape player, if anyone remembers this must have product from the late 60's, and also the Lear jet the first personal small Jet for the business person, to run a steam powered car but this one never made the race.  

A team running a gas powered car through unsafe practice in refueling managed to have a fire in pit lane. The problem was that some over zealous marshall doused the fire with water and since gas floats on water the fire was spread instead of extinguished and set almost the entire pit lane on fire. The sanctioning bodies solution was to ban all fuels except methanol because methanol can be diluted and put out with water.

Question: Why don't normal passenger cars use methanol?

Well it isn't because you can put out a flaming econo-box with a garden hose. The two main reasons are cost of the components you would need on the vehicle to handle the fuel and the absence of the infrastructure for refueling. All alternate choices of fuel suffer from reason number two. There has been attempts to introduce alcohol as a fuel even back in the late 1970's. A team in the Daytona 24hr race ran a substance called gasohol to try and prove its merits and I believe that it was actually available at the pumps in certain places, but the hype seems to have died. There are however fuel manufacturers using the "natural octane" of methanol and the substance is used to mix with gasoline as an octane enhancer -- one of the ways to bring up the performance level of the fuel since the banning of lead in fuel has left a bit of a void in high octane fuel availability. Apparently when mixed with gas the corrosion problems of the alcohol are kept under control.

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