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Maintenance & Repair What about fuel types & gas mileage?
281 messages, Last post on Sep 22, 2009 at 3:52 PM
You are in the Maintenance & Repair Forum. Your Host is mr_shiftright
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Replying to: elias (May 09, 2006 12:23 pm) I guess what I was driving at is the common misconception that premium fuel is some kind of "doggie treat" for your car 
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Replying to: Mr_Shiftright (May 09, 2006 12:18 pm) Absolutely, positively no argument from me. I thought we were discussing the GTO which per a recent post requires 91 octane or greater, not a car that carries a recommendation of 87. With your comments in mind, I'm thinking that in theory at least, it is possible to design a normally aspirated engine specifically for 87 octane, and then design the ignition system to be able to nominally take advantage of a higher octane fuel. That having been said, in reality my bet is that advancing the timing on such a car far enough to take advantage of fuels beyond say 89 octane is probably not going to happen. Best Regards, Shipo
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Replying to: shipo (May 09, 2006 12:27 pm)
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Replying to: Mr_Shiftright (May 09, 2006 12:27 pm)  Best Regards, Shipo
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Replying to: shipo (May 09, 2006 12:29 pm)
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Replying to: Mr_Shiftright (May 09, 2006 12:31 pm) Best Regards, Shipo |
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a lot of modern engines and transmissions adapt to 'your driving style'. my pzev focus has a manual transmission, no tach, and an upshift light(flashback to the 80's). one time i filled up with 93 octane. got my worst mileage ever, 24.9 average for the tank, and the upshift light never came on. for the life of the car i have averaged 28.9 mpg. my explorer seems to run quieter on high test, but the mileage in not necessarily better, except when using winter gas in a cold snap.
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Replying to: explorerx4 (May 09, 2006 5:19 pm) In the case of the Focus, there is no surprise that your mileage went into the dumper, Premium fuel simply isn't volatile enough for that engine. As for your Explorer, unless your engine is heavily carboned up on the inside of the combustion chambers, Premium gasoline shouldn’t make it run smoother at all. In fact, due to the effectively cooler burn that results from high octane fuel and a low compression engine, all you are doing is accelerating the process of carboning up the combustion chambers. Once enough carbon builds up, then "Hot Spots" can occur, and when they do, then you really will need Premium just to keep the engine from running in a constant state of detonation. Best Regards, Shipo
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Replying to: shipo (May 09, 2006 5:36 pm) with the explorer v8/auto/towing pkg, it seems like the transmission got out of sync with the change in the operaion of the engine. back to regular gas, everything is as was before. what do you think about switching brands of gas because they have different formulations?
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Replying to: explorerx4 (May 09, 2006 6:21 pm) Regarding different formulations, logistically speaking I just don't see how one brand can actually sell different gasoline than the next due to refining and transportation issues as well as various efforts at standardization such as the "Top-Tier" gasoline program. I'm sure this wasn't much help but there you have it. :-/ Best Regards, Shipo |
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Maintenance & Repair What about fuel types & gas mileage?
