Quote:
Originally Posted by Tranas
I've always wondered the facts from the fiction when it comes to the three (or more) types of gas you get to choose from at the gas station.
I was wondering if it's smart to use the highest "premium" version on the fit, to keep it in a better condition? Considering we only have a 9 gallon gas tank with great MPG - a few extra cents a gallon should be no big deal.
But I'm curious if it's actually even worth it?
Can anyone shed some light on the difference between the types of gasoline? Is it just an elaborate scheme to waste accumulative cents for a false reason on the unknowing?
Thanks.
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The difference between regular, intermediate, and premium gasolines is based on the octane rating, or the ability of gasoline to avoid combustion from compression heat before ignition by the spark plug. The higher the engine compression the more likely to get precombustion, or spark knck,. It has a knocking sound like rapping on a hardwood surface, hence the name. reg is 87 to 89 octane, intermediate is 91 and premium 93.
our Fits don't have a high enough compression to warrant more than the regular gasoline.
However, gasoline does leave deposits that can inadvertently raise commpression and the best way to avoid that is monthly adding one can of injector cleaner to your gas. WallyWorld sells a good non-alcohol one at about $1.50.
The only reason to ever use premium is for slightly higher mpg as premium's mixture of component chemicals has a somewhat higher energy content so you get more 'push' from its combustion. Usually though, the added cost doesn't justify the gain in mpg.
PS all gasolines are a combination of many chemicals; they may vary even from the same brand simply because refineries are that fixed on processing conditions and selection of crudes.
We had the chance to talk with some of my lab people and they said gasolines in general were losing energy potential. Some heats of combustion measure as low as 108,000 BTU and even premium isgetting results as low as 111,000. Has to do with increasing volume output from the same crudes. In general premium still has a slightly higher Heat of combustion but it still isn't worth the price increase.