Using 93 Octane gas is bad for my engine?

Chonk · **Using 93 Octane gas is bad for my engine?**

I just got my 2001 Mustang serviced this weekend. While I was talking with the guy at the service department I asked him to look into a slight rapid tapping that I could faintly here at 3rd gear 2000rpm (it's under warranty, I figure I should get everything I can out of it :p ). The guy asks me what kind of gas I use. When I told him that I only use 93 octane he tells me that my car was designed to run on 87 octane gas and running gas of a higher octane leads to that noise and can possibly harm my engine over time. Is that true? From my limited understanding of engines and gas I don't see how this could be.

Also, can anyone recommend a good auto show in Charleston, SC for Mustang mods (exhaust, gears, CAI, maybe nitrous).

Thanks

Monkey · 12-14-2003, 11:03 PM

yes, the car was designed to use 87 octane. excess octane can corrode the spark plugs and clog them in a sense. you will not see any extra hp or benefits using a higher octane other than a smaller wallet.

Ponycarman · 12-15-2003, 06:09 AM

Using a higher octane gas than specified will NOT hurt anything. However, using a lower octane gas than specified can. Other than wasting money there is no problem using 93 octane.
And NO higher ooctane gas doesn't clean the engine out anymore than 87 octane, my wife thought it did thanks to those stupid commercials.

Steve

Chonk · 12-15-2003, 07:05 AM

Thanks for the quick answers!

Monkey · 12-15-2003, 09:03 AM


Quote: Originally Posted by Ponycarman Using a higher octane gas than specified will NOT hurt anything. However, using a lower octane gas than specified can. Other than wasting money there is no problem using 93 octane. And NO higher ooctane gas doesn't clean the engine out anymore than 87 octane, my wife thought it did thanks to those stupid commercials. Steve

when i bought my car, the dealer told me "dont use anything higher than 87. the spark plugs we use in these cars are designed for 87. if you go higher, you can ruin them and not get the full 100k miles out of them.

stangin99 · 12-15-2003, 10:02 AM

Quote:

Originally Posted by Monkey


Quote: Originally Posted by Ponycarman Using a higher octane gas than specified will NOT hurt anything. However, using a lower octane gas than specified can. Other than wasting money there is no problem using 93 octane. And NO higher ooctane gas doesn't clean the engine out anymore than 87 octane, my wife thought it did thanks to those stupid commercials. Steve

when i bought my car, the dealer told me "dont use anything higher than 87. the spark plugs we use in these cars are designed for 87. if you go higher, you can ruin them and not get the full 100k miles out of them.

you will always run into problems trying to get 100k out of your stock plugs.

RGR · 12-15-2003, 01:17 PM

Excessively high octane use (like race gas, ~100 oct. +) in a street car with stock
C.R. and ignition timing can cause exhaust valve burning, and this
thinking has been abused to assume that using slightly higher octane
hurts things, but just a few points higher octane is "in most cases" not
harmful, but unnecessary. I'm just awed that OEM's now (finally) utilize
higher CR's with lower octane fuels and get great performance. Our latest
CR is ~9.4:1 and te old "Rule of Thumb" for octane would say that needs
94 Octane!!! (just move the decimal) but we can use 87 8) and still
get great mileage, power and drivability... If we add ignition timing via a
chip or the "free timing mod" we can then actually need premium fuels,
but there is a point of diminishing returns that is usually dictated by $$$
rather than running out of octane or HP...

Danger Dude · 12-15-2003, 02:01 PM

Quote:

Originally Posted by Monkey


Quote: Originally Posted by Ponycarman Using a higher octane gas than specified will NOT hurt anything. However, using a lower octane gas than specified can. Other than wasting money there is no problem using 93 octane. And NO higher ooctane gas doesn't clean the engine out anymore than 87 octane, my wife thought it did thanks to those stupid commercials. Steve

when i bought my car, the dealer told me "dont use anything higher than 87. the spark plugs we use in these cars are designed for 87. if you go higher, you can ruin them and not get the full 100k miles out of them.

I have yet to see any of these 100,000 mile no maintenance engines go the distance without having a tune up. typically wires, plugs go first

Monkey · 12-15-2003, 03:33 PM

Quote:

Originally Posted by Danger Dude

Quote:

Originally Posted by Monkey


Quote: Originally Posted by Ponycarman Using a higher octane gas than specified will NOT hurt anything. However, using a lower octane gas than specified can. Other than wasting money there is no problem using 93 octane. And NO higher ooctane gas doesn't clean the engine out anymore than 87 octane, my wife thought it did thanks to those stupid commercials. Steve

when i bought my car, the dealer told me "dont use anything higher than 87. the spark plugs we use in these cars are designed for 87. if you go higher, you can ruin them and not get the full 100k miles out of them.

I have yet to see any of these 100,000 mile no maintenance engines go the distance without having a tune up. typically wires, plugs go first

i know, ive already replaced mine twice and i have 50k miles on my car.
im just saying what the dealer told me.

oh, and if you tell me twice is too much for a 50k car, i will tell you that once was me swapping copper plugs when i had nitrous and new plugs in after that

Ponycarman · 12-20-2003, 06:18 AM

hmm,

Exactly who at the dealer told you that?

The salesman?

It's, how shall I say it, ah yes, the warmed leavings of a male cow.

Steve