gasoline? do you know what gasoline is? It is like saying Wine. anything could be in it. Sake is rice wine. I like plumb wine too. Gasoline is a bunch of random crap. it is IMPOSSIBLE to say that a gallon of gasoline has this much btu's. do you know that way over 30% of your gasoline isnt even power producing material? An oxygenate allows the hydrocarbon to burn efficiently. Lower presence of oxygen stifles the reaction.

ethanol also increases octane rating. It is actually GOOD for person who has a high compression engine. There are other better ways that certain engines like to gain octane, but this the cheap, environmentally healthy way.

your car uses very little of the energy in the gasoline mixture. additives and things that raise octane ratings help the energy of the hydrocarbon to be more realized. While one might have a very high amount of energy in it versus another, that doesnt mean that energy is used when you are on the highway doing 80 mph. Take hydrogen and oxygen mixed with an electric spark. The energy in it is kinda meaningless as compared to the expansion of the gas. They are related of course, but one doesnt have much to do with the other. Check out aluminum and iron. mix them with a stick of magnesium. light the magnesium. ENORMOUS amount of energy is released. wont push up a cylinder in your car though. However, it would melt through your engine instantly and make a puddle on the cement of liquid mag-ma (dr. evil)

I have listened to old foggie types complain about ethanol in gas (I dont think youre that type, they have no idea about btu tables!). They think that new gas is power robbing. In fact, ethanol and modern gas is very useful, healthy and a fine fuel if your car is a modern car. These types want to go back to leaded gas. They have no idea how terrible gas was back then, how inefficient it was and that was why lead was put in it! Those cars with massive power and acceleration got like 9-11 miles per gallon. I could get a scion TC to get 500 hp with a set of turbo chargers running on 10% ethanol. Both situations are wasteful of gasoline yet get you power because the engines were designed for those fuels.

ethanol, methanol, acetone, toluene all are great to use but do very different things that the engine has to be built for to use properly. Xylene is pretty neat too.

 

Also too, check your tyre pressure. This time of year it is very likely to loose a few lbs off each tyre. And since the tyre pressure loss is pretty even between your four tyres, the sensor will not go off. If you are at 28lbs, instead of 32 to 36 that could mean a difference of 2 to 4 mpg.

 

Every car since the seventies can handle E15, which is 15% ethanol. And increased ethanol will decrease mileage, but not by 10mpg – more on the level of 2-3. Decreases in the winter are likely because of different cocktails, don't go blaming the ethanol solely.

 

Hmmm...are you are about that? Higher revs mean more boost and more boost means more gas being squeezed in the cylinder. My instantaneous gas mileage (on the OBC) drops like a rock if I push it well past 4-5K RPM.

 

3k is not 4-5k

after 3k gas gets eaten, but around that or around like 3200 rpm, I get great gas mileage.

i mean that almost any other car at 3-3.5 gets terrible gas mileage while my mini is fine at those rpms. I think it has to do with weight.

 

If you have a MC S like me , here is what happened to my mileage

I am heavy modded (and expect some drop in mileage) but really started getting BAD mileage.

Long story short my By Pass Valve was not fully closing ... result much lower vacum (reading off my boost gauge)

Driving while maintaining the highest value of vac is the most economical.

After changing the BPV to a Detroit modded one, I had better vacum, performance and much better mileage.

The BPVs are known to go bad.

I have some photos of the old BPV in my gallery.

Hope this may be of help

Still I understand that there are MANY variable in MPG calculation