octane

[ddgrave321]

MY ecu says 93+octane and is it fine filling it up with 92.

and is there any negatives about putting lower octane?

[elitefew22197]

I didn't even know they made octane 92 haha. Someone correct me if I'm wrong, but I think it depends on what octane the engine was tuned for. And if you fill with lower octane and run the engine hard it could lead to knocking and detonation If your tank is almost empty, and 92 is all you can find then fill up and take it easy. If you have 93 readily available I would just stick to that and have peace of mind.

[biggie]

Says he has SRDET and 93 on ECU. Lower octane possibly equal engine go boom.

[ddgrave321]

would octane booster help that problem out?

Def would not want my engine to detonate at any point

[biggie]

Octane booster really doesn't do much at all. Just keep running the 92-93 octane.

[walperstyle]

What compression pistons do you have?

[the converted]

If you can't find the 93, I'd pull a few degrees of timing to keep you safe.

[ddgrave321]

im running stock boost and internals so im guessing around 9.8 compression or whatever stock is? what do you mean pull a few degrees of timing?

[compactfean]

Unless you have some sort of engine management or ignition controller, you can't just ”pull a few degrees timing”. When adjusting the distributor it adjusts ign timing and injector timing. The car won't run right is the injectors fire to soon/late. Just leave the dizzy at where its supposed to be. Also places that have 93 octane all over the place need to sell it as there premium because of there elevation. Lower elevation will cause detonation and leaner conditions. In higher elevation the extra octane isn't necessary for most stock tuned vehicles.

[the converted]

Actually, yeah you can just pull a few degrees if you need to. The couple hundredths of a second delay in the injector won't effect performance nearly as much as you're making it out. A fraction of a horsepower maybe. If you thinking that from the factory that injectors are sized to have their duty cycle around 80% at peak output, that means that most of the time the injector is spraying on a closed valve regardless. In a perfect world, yeah you'd do it differently, but if you can't get your hands on 93, it'll work just fine.

[2_Liter_Turbo]

I ran 91 octane california crap gas for years on my sr when it was stock (but at 13psi). No issues whatsoever. I run 92 up here in Oregon with no issues as well. You'll be fine as long as it's a stock tune on a basically stock setup.

[ddgrave321]

ok thanks guys

[mechanicalmoron]

I could be wrong, but the stock ECU should know what's up, and as long as you don't pull away from the pump at WOT or go tracking 87 octane, I wouldn't worry.

For starters, I think japan uses the octane system the rest of the world uses..... they have higher numbers for the same thing. 91 pump should be fine, just buy the best available to you.

I'd worry more about crap like phase seperated or overblended ethanol. Some small airports or marinas can allegedly sell you cat safe avgas, though some may be leaded as it's better with cold and moisture than the other normal anti-knock additives, though it's apparently expensive and I've never done it.

[2_Liter_Turbo]

You can run leaded gas just fine (without a cat), but be prepared to go through a few o2 sensors a year, lol. A buddy of mine ran leaded gas for a couple years, but he was fine with replacing o2 sensors.

[mechanicalmoron]

You can run leaded gas just fine (without a cat), but be prepared to go through a few o2 sensors a year, lol. A buddy of mine ran leaded gas for a couple years, but he was fine with replacing o2 sensors.

Just make absolutely sure you have no cat and no other emissions stuff, like an EGR or anything.

Shouldn't hurt engine internals, but it will be a lot harder on all your exhaust stuff. And make your car generally much more toxic to do pretty much ANY thing to, from oil changes to fuel filter replacement you'll be exposed to lead.

Personally, as lead is toxic in ANY amount and the damage is cumulitive, that would scare me.

[compactfean]

They make lead substitute for fuel additives if lead is absolutely needed.

[mechanicalmoron]

They make lead substitute for fuel additives if lead is absolutely needed.

I could be wrong, but I think it became illegal to buy or sell lead gasoline, but not to burn it, as long as you don't disable emissions on a controlled vehicle.

I think lead substitute may just be substitute lead, otherwise why wouldn't they just call it octane booster, just like the rest of them?