6G Celicas Forums

is there any difference in power/gas mileage/how well the engine runs? if so, how much of a difference in each?

there is a difference, not a HUGE difference, but for me it does feel like the engine runs a bit better with 93. But like I said, its not huge, and since gas over here in florida is about $2.60 for 93 octane, i'll stick to my regular unleaded ;-p

what kind of mods do you have? If ur stock, you don't really need to be running 93, it's pretty much pointless. If you really want to though, I'd suggest going half 93, half 87. It'll cost less, and it's a old muscle car thing that for some reason mixing half and half is actually better than going straight up w/ 93.

pointless?

it can be damaging...
stay 87 until you need better.
and if you do go up i'd get better spark plugs and wires.

How can it be dangerous, We drive on 95, 97 and 98 octane.

Or maybe i am mistaking some stuff

I've ran 93 in everything I've ever owned. Unless you have your ECU set to 87 or 89 gas, I don't see how it could hurt anything. They only do this on newer high end cars, like Cadilacs.

rofl..... if you mix the two you end up putting in 91..... just put in 91 from the pump.

ask the gas station attendant. he will tell you the same thing

my gas stations dont have 91. The one i go to has 93 and 87 lol. And I was just repeating what the domestic homies say

noobs helping noobs. Google the question - there is a ton of information out there.

hahahaha nice one


open up your owners manual and put in the type of gas it recomends. easy!

This post has been edited by lagos: Apr 21, 2005 - 2:42 PM

i asked jeeves to double check myself...
read up:

WHAT IF I PREFER TO USE GASOLINE WITH HIGHER OCTANE RATINGS?

You can, but there are no real benefits, other than the gasoline manufacturers making more money off of you. When you use a fuel with a higher octane rating than your vehicle requires, you can send this unburned fuel into the emissions system. It can also collect in the catalytic converter. When you over stress any system, it can malfunction or not do what it was designed to do properly. In the early 90's, an early warning symptom was a rotten egg smell from the tailpipe. Easy fix, go back to using regular 87 octane gasoline. The rude odor usually disappears after several tanks of gasoline.

DOESN'T HIGHER OCTANE GASOLINE HAVE MORE CLEANING ADDITIVES THAT ARE GOOD FOR MY ENGINE?

No. Government regulations require that all gasoline contain basically the same amount of additives to clean the injectors and valves. The only differences are the type to help create the different octane ratings. All gasoline burns at the same rate, it is the additives that create the different octane ratings for the different types of engines.

Unless your ignition timing is advanced a few degrees, you shouldnt have to, or need to, go any higher than 87. The only reason to go for higher octane when running advanced ignition timing is so that you dont get any detonation.
Correct me if I'm wrong..

nope, i agree...higher octane is to prevent early det.

In the USA they use a different way of rating octane than in Japan, NZ, Netherlands etc.

There are 3 main ways of testing the octane rating: RON, MON and PON.

We use RON (Research Octane Number), whereas in the US PON (Pump Octane Number) is used - which is an average of RON and another way of rating octane called MON (Motor Octane Number)

So when someone in the US says they're using 92 it's the same as our 96:

RON 92 95 96 98
MON 85 87 88 90
PON 88.5 91 92 94

Hope this helps

Click here for more info.

This post has been edited by neophile: Apr 22, 2005 - 2:30 AM

wow, that's new to me, ThX Neo...

edit: btw i really dont see it being harmful for the engine to use higher octane, but a huge waste since there OEM ignition system is pretty weak, the lower octane can help deton. occur at the right time. I only see octanes really mattering with huge compression ratios and F I'd vehicles where the cylinders have enough pressure inside to get knock...

This post has been edited by Consynx: Apr 22, 2005 - 9:11 AM

from what i know....using a diff octane than what the car is made for screws up the timing and makes the timing retarded(a phrase ive heard...im not making it up). this has to do with the detonation being early or late. when you add performance mods and increase boost with a turbo or supercharger...you increase the preassure and the lower octane gas can detonate too early...that is why you use higher octane when you have more mods to keep the timing right. overall...you probably wouldnt notice much difference between 87 and 93 for our cars unless you have mods, so using 93 is a big waste of money and too much fuel sent to the cat can damage it like consyx said...basically there is absolutly no point for a stock engine made to run on 87....you could save the money and use it for mods!