itsme

for you F/I guys out there what octane gas do you use? is high octane required for F/I for daily driving and so forth?

Baine

I only run premium.

EVLTSTR

Yes... The higher the better. 91 at minimum. 92 or 93 preferred.

rollhard

you need to run premium, and good premium if you go FI. For those who are not running FI, regular is best. You will get no benefit at all from premium.

TRDXA06

why is it that you dont get a boost in power if you run premium without a turbo in a scion. on my pops 05 pathfinder when we switch back and forth it is a huge differnce and there no turbo on that either and its a relitivaly new car as well.

BoogieQ

Higher octane burns slower, and cooler. If you get a gain from using 93 in a car that isn't boosted, it's because your motor isn't running right to begin with and you are eliminating knock and gaining back timing advance.

Under boost, you need the slower cooler fuel to help compensate for the increased compression with the boost. Higher octane is less likely to predetonate under the increased compression.

rollhard

That could be more mental power than anything. If you really want to know, take it to a dyno and also measure your mpg. You or your dad could very well be paying for something that you dont need or arent benefitting from. Use the gas that is recommended by the factory. For our stock XBs, we should use regular. Anything else, you are just wasting your money. Like Boogie said, if you noticed what you called a "huge difference", your car wasnt running right to begin with. Also, the Pathfinder runs the same VQ35DE engine found in the maxima, 350z, etc. That engine requires premium gas. So.......you putting regular was a no no.

Jhhnn

From rollhard-

"you need to run premium, and good premium if you go FI. For those who are not running FI, regular is best. You will get no benefit at all from premium."

I think that's only half right- the owner's manual specifies 87 octane, which is midgrade around here, and about right for the relatively high compression ratio. Regular is 85 octane, meaning that the knock sensor will tell the ecu to back off on the timing, reducing both performance and mileage... You're right that premium doesn't offer any real advantage...

My box purrs happily on midgrade Conoco...

chorobe

I agree you have to use good quality premium, I used to use Costco premium but going from that to a more well known brand made quite a difference, so I don't use the cheap stuff anymore.

Baine

My Costco uses BP gas and it's $0.15 cheaper than anybody else.

chorobe

I'm not sure which one the nearest costco here uses. I do use costco gas on our minivan, no big deal there, but for the turbo I usually go with chevron.

rollhard

85 is regular there???? WOW. Yeah, when I said regular, I meant 87 octane. My appologies. Whats race gas there? 91 octane?

evosky

yeah, octane ratings and availability vary waaaaay too much depending on region in my opinion. here in DE, the typical regular is 83 or 85 . i usually end up putting 83 in my tank. super is 85-87 and premium is 91 . rarely are there stations with 93 or higher. sucks.