What Octane Grade Fuel for 3800 SC?

AA can you sticky this thread? It seems to come up all the time and NOBODY LISTENS.

Have a nice blown motor.

It is stickied in the Supercharged FAQ:

https://rivperformance.editboard.com/series-ii-engine-transmission-f4/series-ii-supercharged-faq-t1585.htm

This link is contained in the Welcome thread. I can't help if people don't read the FAQ, but I can merge their threads if they post. Unfortunately, we can't individually sticky every thread that's important, because there are just too many. It would make clutter at the top of the forums.

what about 95 or 100 octane, a gas sation by house has it for $5.28 a gallon and for 100 for who knows. Is it worth for the 95 or would 100 octane be safe for 1996 riv supercharged.[/b]

where do you live??

1996RIV CALI wrote:

what about 95 or 100 octane, a gas sation by house has it for $5.28 a gallon and for 100 for who knows. Is it worth for the 95 or would 100 octane be safe for 1996 riv supercharged.[/b]

You do NOT need to spend the money for 95 or 100 octane for daily driving. If you're unmodded, or mildly modded, 91-93 octane should be just fine. More is not always better. If you don't have KR, you're just throwing money away on anything higher than your local premium gas.

thanks for the info. I live in Oakland ca bay area.

Well I'll see you on the field!

(Chargers Fan)

Shintsu wrote:

[Forunately the gas station I went to was out of 87 and 89 so I had no choice but 93!

Are you saying you usually put in 87 or 89?

deekster_caddy wrote:

Shintsu wrote:

[Forunately the gas station I went to was out of 87 and 89 so I had no choice but 93!

Are you saying you usually put in 87 or 89?

yes he does......... this was in a previous thread..........

Coming from someone who has owned several Premium only vehicles and ran 87 in them, running premium is overatted. I DO run 89 in my Riviera though, being supercharged.

I for one don't follow hype.

manofmany wrote:

Coming from someone who has owned several Premium only vehicles and ran 87 in them, running premium is overatted. I DO run 89 in my Riviera though, being supercharged.

I for one don't follow hype.

Knocking or detonation is a pretty neat thing. It can occur for a long time unnoticed and then other times it can happen for just a moment and blow a chunk of piston through the oil pan. Have fun playing russian roulette with your car.

lots of cars say they need premium gas from the factory so that they can run at the optimum ratings. some cars, like boosted ones, NEED higher octane fuel to prevent engine damage. we fall into the NEED category.
buy a scanner and prove it for yourself! my only motive is helping other riv owners preserve the riv. i dont gain or lose anything based on what gas you choose.

If you aren't running premium, you are doing what I call "running against the knock sensor". One mistake from the knock sensor and you're done for. Also, the way the knock sensor works - first it has to hear detonation. Then it reduces timing until the detonation clears up. Then it adds some timing back to see if the detonation is still there. If yes, keep the timing out. If no, try some more until stock amount of timing is reached. Repeat. Repeat. Replace head gasket (or worse, see Turtle's pic above). Repeat.

It's not hype. It's for real. Especially if you ever use full throttle, or your torque converter lockup (which you do).

I'm in agreement. The Honda Prelude never got the premium it wanted, the boosted cars though.....mmmmmmmm Octane is key.

How much of a difference does it make when you got a stock car and run 91 or 93. I filled it up from empty today with 93 and it seemed a little more peppy compared to 91. Or could this just be in my head? It was pretty nice though since the 93 is cheaper than the 91. I went out of state today and gas is cheaper there then in minnesota.

Premiunm can be hard to find. My mom lives in a town of 1250 people and I cannot find premiumn there to save my life. Last time I just barely had enough to get to the next town where I could buy some. I will not run anything else but 91 or better in the riv especially when its like 10 cents more expensive here. I think it is a cheap insurance policy.

The only way to be sure is to hook up a scan tool and find out. I have been tuning my car for 93, I'll be sad if I can only get 91.

Being that our pcms learn knock and fueling. You want to run premium all the time or wait for the pcm to adjust (or reset it) for the fueling to take effect.

I can't feel the difference between 91 and 93, but scanning shows more knock with the lower octane. I don't just want the car to be faster, I want my pistons to last longer, so I go with the highest octane I can find.

riviera2454 wrote:

I filled it up from empty today with 93 and it seemed a little more peppy compared to 91. Or could this just be in my head?

Nope, same here. It's definitely filled with more get up and go.

use 110 leaded, get lead safe O2 sensor's........... OR use E85.......

screw 87-94

91 will work just fine if the car is in the stock form correct? All I can buy around my area is 91.

Yes, it's fine for a stock engine.

I use only 93 mainly from chevron!

Gotta problem......the Riv doesn't like it here too much.....the best gas I can buy here has 20% ethenol and knock has increased 3 times....on wot its hitting 13 degrees....I havent had the time to use the DHP yet to tune and the headers/new exhaust is a few months away....anyway....can I use jet fuel and mix it or use it straight? The octane here for primium gas is 91, the jet fuel is rated at 105.....