is 93 octane too much?

[dirtymoosetaint]

SO i stopped at a gas on my way to work this morning cuz i was was abotu to run out of gas. It's not a ags station i woudl normally stop at but i noticed they had regular, mid grade, premium and ultra 93, so I got the Ultra 93 I have to say i can tell a difference a good difference but is it to much for my little scooter..lol

[inuyasha]

Hi
Your going to get many differing answers
Imho Use the octane that enables your scoot to operate efficiently and properly, IE no detonation
I use 93 or 94 in "April" but she has an 11:5 to 1 compression ratio
Take care and ride safely dear friend
Yours Hank

[Deleted]

93 always.

[dirtymoosetaint]

cool cuz i noticed that it runs and accelerates alot better since putting in the 93 and i really like it lol

[drbenz]

The normal is to use whatever grade of gas that is recommended by the manufacturer which is going to be based on the compression ratio, the higher the compression the higher the octane grade needed. Having said that, the only thing "too high" of a grade of gas will hurt is your wallet. If you can see a difference use the higher grade.

[tango]

I have topped up the tank on my Taotao twice in a week and both times I did so with 93 octane. The premise behind that is the 4T engine is a very old, simple design and that usually means it is less knock resistant than a more modern design. 93 gives me a little extra protection. For the record, I topped up (from about 1/2 tank or so) the first time with $4.31 and $3.81 the second time. At those numbers, a few pennies difference in fuel cost is practically insignificant.

[black2]

Any octane above what it takes to prevent pre-detonation or "knocking/pinging" is wasted unless you tune your vehicle to take advantage of higher octane fuel by running more advance or rebuilding to a higher compression ratio. These simple engines don't have knock sensors or variable spark timing or any of the stuff that enables modern auto engines to run different octane fuel. My vehicle requires 90+ octane premium, but that isn't always available so if you put regular or mid-grade in it, it just retards the timing so that it won't pre-detonate and the already bad gas mileage gets worse.

[tango]

That's precisely why it's safer to run the highest octane possible in these engines. They can't compensate for the lower octane fuels and damage could result. The Chinese brands have such poor quality control that I wouldn't trust what the manufacturers say we should use. Using higher than required octane won't damage the engine, but running lower could.

[revweasel]

at 50 to 100 mpg 25 cents per gallon makes no diff in fuel cost. and premium is going to be much less likely to be gasahol. in most states anything not premium has ethanol.

[drbenz]

This is a most interesting article on the subject: www.scootnfast.com/index.html

[tango]

Nice site. It pretty much backs up what is being said here. Indeed there is no power to be gained from higher octane fuel itself, BUT if the engine timing is being retarded due to signals from the knock sensor then the engine will lose power. The only way to get that power back is to eliminate the knocking, which is where higher octane fuel (if the cause of the knocking is too low an octane rating) comes in. So by default, the higher octane allows the engine to build more power under those circumstances. A similar situation would obtain for fuel economy. Our scoots do not have knock sensors and there is no automatic retarding of the engine due to knocking. Therefore that low octane fuel will continue to cause knocking and then detonation to the detriment of the engine. Therefore the few extra cents that 93 costs is worth it to me, though it may not be mandatory.