So I get 89 octane fuel sort of for free. My family's corporation purchases it in bulk and I sometimes get some free of charge.

I've done the research and it seems it would be fine to run in a 4g63t I would just lose MPG and performance.

If I'm okay with those setbacks can I go ahead and take advantage of the fuel deal? Should I get a MBC and turn the boost down or just leave it stock? Will going to WOT cause knock or will the car detune itself to the point I won't have to worry about knock?

Thanks for any insights!

I do not think you can turn the boost down from waste gate pressure with a mbc, however I have been wrong a few times in my life.

It would be as easy as hitting reset octane value,in link,or on a chip,or the black box ecu.
Maybe back timing down a notch as well.

keep it at stock boost and you'll be fine

It doesn't say he has link. If he doesn't have a mbc I'd say he doesn't... it will be fine, I've filled mine up a couple times in the past when money was rough and I needed more gas to get around than performance for my buck.

If you start to knock on boost, which I don't know if you will on stock boost levels, the knock sensor will pick it up and pull timing.

I personally didn't even notice a difference going from 91 to 89 when i did and i run/ran 18psi... its not like you're going from e85 or race gas to 89.

You can tune it to run fine on 87 if you can pull enough timing. Car may run like shit, but it'll be drivable. I've used 87 in 4G63T cars being driven long distances in the past where I knew very little if any boost was going to be built. The cars ran just fine and no damage was done.

Although, it makes me wonder the consistency of fuel you're actually getting. I know a guy who owns an manages a local gas station and he claims Plus and Super/Premium make up less than 5% of total fuel sales with Super/Premium being even just a small percentage of that 5%. If the car before you bought 87 and you buy $20 worth of Super/Premium, nearly a gallon of that is going to be the 87 that's stuck in the pump and hose from the guy who bought fuel before you UNLESS the pumps are old-school and have three different hoses like a handful of places in my area. Dilute it down enough and you may not be getting octane you're paying for.

Exactally why i dont buy from single pump places.

He was saying 89, which isn't as big of a jump as 87. But same difference.

I can't even think of anywhere here anymore that runs more than 1 hose, unless it has diesel on it.

Utah sucks for fuel anyhow, only two stations with e85, one is far and the other is in bfe. Only a handful of places have anything higher than 91 and it's quadruple the average price of $3.50/gal for 91...

It's 5.80 for 94 here in canada, e85 also non existant

I'm sure if we had 94 it'd be up there with that, we have a station here with an old school pump that spits out 100 octane, last time I went there to get a few gallons it was $12.50/gal.

C16 120 for 5 gal

Thats $25 per gallon

Breezio69 said:

I'm sure if we had 94 it'd be up there with that, we have a station here with an old school pump that spits out 100 octane, last time I went there to get a few gallons it was $12.50/gal.

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You can get 110 here for like 7 bucks a gallon. It is leaded though, but smells amazing.

bryanwheat said:

You can get 110 here for like 7 bucks a gallon. It is leaded though, but smells amazing.

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Yeah, I've seen that leaded stuff, isn't recommended for sensors and whatnot, but i have seen its a fraction cheaper. The stuff that supposedly comes out of the pump is Sunoco unleaded 100? If it really is I couldn't tell ya?

And I know about those lovely jugs of race gas, I used to get vp112 for my quad for i think $95 a few years ago... it was running 14.5:1 compression and would ping ("knock" term in single cylinder applications) if I didn't mix it 75/25... of course the 25% was the 91 and I'd go through it all on a weekend trip to the dunes sadly enough. Ok, $25 in food, $50 in booze, $175 in gas, lets go!


Derail. Lol

Vp fuels arent even easy to come by here. Theres one dealer in all of ontario (not including speed shops that jack up price.)

Yeah, the only reason I ever bought it was for the quad, I regretted going that high on the compression the minute I started it after the rebuild. She was a beast though

I was hoping a new full size natural gas station built downtown here would start carrying e85... But no, full station of cng only.

C16 is 25 a gallon there? I can get it for 9 a gallon here

I think it's cause VP is an american company and therefore we are subject to import charges and then 13% tax

I used to live in Alaska and the highest octane you can get is 90 but even then a lot of gas stations don't sell anything but 87. Out of necessity I've had to use 87 in my current GSX and it was fine. I just made sure to stay out of boost. Didn't record any knock at all.

actually a fairly large percentage of what gas stations sell out of the fuel pump can be water (up to 7% i think, been a while since i did installs at gas stations) and most gas stations that are single line do not carry mid grade, they mix high and low to get mid. and yes, premium is a tiny percentage of sales. and if you are buying from a place that says they carry 100% gasoline THEY ARE LYING OUT THEIR BUNG HOLE.

what you get from a gas station is not what you think, what i tell people is try gas stations until you find one that works well in your car and then NEVER switch.

I just realized i was wrong, all our pumps are single pump. Range from 89-94

Worst case just run some octane booster (you'll probably need quite a bit), but hey it'll still be way cheaper than paying for 94.

gieri002 said:

Worst case just run some octane booster (you'll probably need quite a bit), but hey it'll still be way cheaper than paying for 94.

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most of that stuff is worse then the fuel from the pump. there are some that do help. just do your research.

Why use 89 in a 4g63? It can be done, but like I've experienced, it runs crappy. 4g63's use the higher rating to prevent detonation, which is why they run like crap with a lower rating. I get 91 or 93 here, I forget which, and that's the lowest I'll throw in my tank.

Wait, are you talking about using 89 in a non turbo car (the one in your profile)?

^^^^ I was wondering the same thing... ^^^^