[AA702]

Originally Posted by jpk

Ethanol will corrode engine parts over time, I doubt one tank would cause any problems. I have a flex-fuel F-150 and can only get Ethanol (E85) at Rebel, not Terrible's. Your fuel filter might have just been old and overdue to be replaced, causing problems in your fuel delivery system.

All grades of unleaded has some percentage of ethanol added, its suppose to be a maximum of 10%, the OP was saying he had 20%, but to know that they would have to get a sample of it have it tested. Your E85 is 85% ethanol and 15% gasoline (theoretically). If your car is made for gasoline only, yes high amounts of ethanol will corrode parts in your fuel system, and yes it can do it over 1 tank of gas if it is high percentage.

[CCCVDUR]

WARNING - Certain gasoline additives (i.e. STP) that are billed as increasing mileage have alcohol derivatives in them (ethanol is a form of alcohol) and should be avoided.


Also, some vehicles including mine due worse on higher octane gasoline (meaning 87 has the best mileage whereas 89, 91, 92 are worse).

If a car has bad gas mileage or low power, it needs a tune-up - spark plugs, wires, timing, fuel filter, etc. etc. etc.....

Plus - One of the things that is frequently overlooked are all the sensors relaying info to the computer, and the electrical connectors. They can become corroded over time, and not send the proper signal to the computer. If the resistance of any connection has increased because something has a bad connection, this can lower power and mileage, and even increase temperature and emissions. Likewise with vacuum leaks.

The Mass Air Flow sensor is one of these that gets dirty. It can be cleaned w/ Mass Air Flow sensor cleaner (DO NOT USE ANY OTHER CLEANERS), but ONLY if you know what you're doing. It can break VERY EASILY.

I did it as a newbie w/ no supervision, and got lucky because the plastic housing was jammed on and I had to physically pry it off with a screwdriver. I had to glue it back together. What a mess! It took HOURS. The car had more power afterwards and less emissions, but it could have been broken and I would have been out hundreds of dollars ..... the MAF is a very expensive part.

And, the wires to the sensor (that go back to the computer) were jammed on, so I couldn't clean them with spray cleaner or check the resistance - so the job is only half done.

I DO NOT RECOMMEND cleaning the MAF unless you follow the directions precisely and use the appropriate cleaners. Most auto parts stores don't even know what kinds of Hexane based spray cleaners are appropriate for various sensors!

There are also electrical connectors to lights. There are so many people who put new expensive halogen headlights in when all they have to do is clean the electrical connectors with spray cleaners to their existing lights.

Mechanics love to take advantage of people when a $5 can of parts cleaner can improve so many things ( NOT brake cleaner!).

Anyone else w/ experience on cleaning sensors including the MAF? It's a popular topic on auto message boards....

Anyway...............all the stuff about the benefits of ethanol and STP cleaners is all a BIG FRAUD and does more damage than good. I'm no expert, but I know that changing spark plugs, spraying dirty sensors, etc. does more good than higher octane gas or using STP additive. 90% of the auto products sold in auto parts stores don't do a thing for mileage. A can of beer (alcohol) in a plastic STP bottle sold for $5 isn't going to help (rant over )

[Kaiminani]

I have to agree with Tom Lane - if your engine was not designed for higher octane gas there is absolutely no benefit to using it. All higher octane means is that the gas will not detonate (engine knock) at higher compression ratios. High performance engines (like those with turbos or superchargers) often run at higher compression ratios and thus require the higher octane gas. But under normal conditions - unless your car's manual calls for the higher octane stuff - there is no benefit to spending the extra money on it.

[AA702]

using higher octane fuel for what your car is recomended to use is a waste of money, unless you modify your engine to use higher octane fuel (such as a supercharger, bolt ons and custom tuning or other power adder). In some cases, it can be harmfull. Keeping your car in tip top shape is also a good idea, so change your oil, plugs and filters regulary. The OP was speaking about ethanol that is added before it gets to the pump which is 10 percent. Another sensor that is neglected is the 02 sensor and works to adjust fuel/air just like the Mass Air Flow sensor. This sensor is located in your exhaust and when not operating properly, can give you a decrease in gas mileage.