Run 91 Octane?

[dwoloz]

Looking at purchasing either a sc300 or sc400

Is it necessary to run 91 octane?

Im rather...umm...cheap :P (maybe frugal is a better word) and Id like to avoid 91 if possible (Its 3 dollars a gallon here )

But if 91 is necessary, Im prepared to shell out for it

[LEXIE]

i have a '93 sc400 and have just gone thru my 3rd full tank of 87 octane

down from 93 and i absolutely see no difference in performance. i dont

"rod" a car and prob stay under 2000 rpm most of the time but even

when i step down hard there is no "pinging" so to speak.

i do mostly town driving and cannot attest to any milage/gal change

but i just love the 20 cents per gal savings.

L

[jzz30]

cars these days have knock sensors that !Removed! timing to help prevent detonation and under extreme circumstances (like turboed cars) the engine will ping even with the sensor because you push the limit. going from 91-87, though not recommended wont do that much because the ecu will sense this and !Removed! timing but you will loose noticeable power. bottom line is if you cant or dont want to pay the extra 5 bucks for premium then maybe you should think about another car. not to be mean or anything but thats how i feel.

[blueviol]

I agree.

How much more will you have to spend a year if you stay with the 91? If you can afford that much for the premium feel and actually smoother and better performance, you'd better stay with the higher octane.

It's like (though not exact) 'would I want to have a cheap burger for lunch or a restaurant-served meal for little extra?'

I have been using 93 all along for my 200K+ mileage.

[RedRocket]

Looking at purchasing either a sc300 or sc400

Is it necessary to run 91 octane?

Im rather...umm...cheap :P (maybe frugal is a better word) and Id like to avoid 91 if possible (Its 3 dollars a gallon here )

But if 91 is necessary, Im prepared to shell out for it

My SC400 has a MPG readout. On a 400 mile trip from San Jose to L.A. and back, I actually got better mileage on the 91 stuff. This WAS NOT a well controlled test and traffic (bad LA) may have had a lot to do with the diff.but it is something to look at. I notice no pinging on either 89 or 91, but afraid to try 87... <_<

[SKperformance]

you wont notice pining with any grade gas unless the engine is overloaded or badly carbonized

the timing will !Removed! once knock is sensed by the ecu