V6 and Premium fuel?

[Rocky1974]

Octane is the fuel's resistance to knocking. They put additives in it that make it slightly harder to ignite. The higher price reflects the price of those additives and how much extra that people who actually think that it is "better" fuel will pay. The V6 may have 11.3 Compression, but it is direct injected, which changes everything. In most engines, knock occurs on the compression stroke, when the fuel is ignited either by the rising pressure or a hot spot in the cylinder. In a direct injected engine, this can't happen. There's no fuel in the cylinder during compression. The fuel is injected directly into the combustion chamber at the last microsecond before ignition occurs. This also cools the cylinder which further reduces chances of knock. This is why direct injected engines run very high compression ratios with very low octane requirements. If knock does occur, there's a knock sensor to pull some timing out, to prevent it from re-occurring and doing any damage. I doubt that these engines are getting very much knock, if any. I'd run 87 in it, if it were mine. I think that you wouldn't notice much gain, if any, from premium. If I were racing it, I might try some higher octane, just to see if there was any measurable gains, but for everyday use, I'd run 87.

[SC2150]

Originally Posted by ernie scar

Your car with the V6 has come tuned from the factory to run low grade octane fuel, keep the money in your pocket. Stick with using the cheap fuel in your car you won’t notice that much, if any change in performance if you are using the car for everyday use.

If in the future you decided to upgrade to the SS or ZL1 then it’s recommended that you use premium fuel in these cars. This has to do with engine knock, etc.

But having said that the computer in the SS and ZL1 can adjust to run lower octane fuel if it had to, but I wouldn’t make this a common practice.

Hope this helps.

The knock sensors detect knock and pull timing before the human ear can hear it, so you should never here it. The Bosch ECU as pointed out has no high & low octaine tables, but it is constantly adjusting timing as detonation occurs and yes, the power is increased and economy slightly better with 93. Will it hurt the engine to run 87? Absolutely not....but the engine is 11.3:1 compression ratio....do a search on octain and compression ratio's. When running 87 you are rarely running at full timing advance, and that is inefficent. On the V8,s that have 10.5-10.7:1 CR, 93 is required. If you run 87, the PCM defaults to the low octain tables and the PCM further pulls timing as detonation is detected.

Originally Posted by MINI HLK

Based on what?

Where is it stated that the V6 is tuned to run on low grade octane?

Please read below,



Until proven otherwise the V6 can adjust to the fuel placed in tank.

As far as net value to the customer who knows. For me .30 cent (premium fuel) increase means my fuel purchase will cost 2.40 more per two weeks. I am ok with 4.80 each month adding to 57.60 for the year. BTW, I only use 8 gallons per two weeks.

Correct that the ECU will adjust to the octaine run, and thats why I would never run 87....but I build these engines day in and day out and see them up close and personal from the inside...and I always want an engine to run at optimine...not just run OK.

Originally Posted by heRS

I ran 93 in mine for a while, all I really noticed was it blacked up the tailpipes I figured it wasn't burning it like it should, so I went back to 87 - tailpipes stay nice and clean now.

That would be impossible...the A/F mixture would not be effected by the octaine. If you noticed it in the colder winter months, the black soot is from the cold start enrichment. Not noticeable in the summer months. But there is no physical way running 93 over 87 could cause black soot.

[MBS]

Originally Posted by mc_acoustic

Just curious...

I have a V6 2010 camaro... I usually run 87 octane fuel....

Is there any benefit going to 89 or 91 or higher?

More horse? Better mileage? Smoother ride?

Just curious since the manual says 87 or higher...

Was wondering if anyone did the research and found out anything

Whatever grade you use ,Make sure it is a top-tier gasoline

[slick rick]

What is a LT1 Limited Edition Camaro?

[Ir0nM4n]

Originally Posted by slick rick

What is a LT1 Limited Edition Camaro?

Only people in the 1LT club talk about the 1LT LE Camaro

[Ir0nM4n]

Nice reply SC2150 !

[OUR72GTO]

Worry less about the octane rating and more about the condition of the tanks where you fuel up. Slow fill means clogged filters and dirty gas. We have a Chevron here that has such old tanks they only cab fill the top 1/2 and have pulled up the intake to take from the top.

[two_wheel_mayhem]

Originally Posted by SC2150

KM is correct. Not only does the 11.3:1 compression ratio dictate 93 for optimine performance, it is also optimine fuel economy. The Bosch ECU is constantly pulling timing on 87 so the engine is not running at peak efficiency thus leass fuel mileage and less power.

Also, as these are direct injection engines, there is no benefit to the additives as no fuel passes the intake valves to keep them clean as in a carb'd or port injection engine.

The reason the engine is designed to run 87 octane with 11.3:1 is because it is a direct injected engine, which changes things. You guys always want to argue with the engineers that design things, thinking you know better. It could handle 13.5:1 easily if GM engineers intended for it to be run on 93 octane fuel, which would probably move it's peak power up to around 350 horsepower. They could also let it turn a few more thousand RPM's with great benefit, but that's another story and is political....warranties. Anyway, the 3.6 runs at maximum performance with the designed fuel. The engineers did not crutch the timing tables just so they could say it runs on 87 octane, that would cause poor economy and emissions.

There's more to it than "this compression ratio requires this octane fuel." That only works when you are talking about a typical pushrod V8 engine with flat top pistons and wedge shaped chambers. Other factors include cylinder head/piston design and material used, bore size, altitude, engine temperature, engine tolerances (specifically piston to cylinder wall clearance), vehicle weight, and gearing.

As far as fuel additives they are all worthless no matter what vehicle you have, at best they boost your octane. If your fuel system gets gummed up no magic in a bottle will fix that. Fuel injection can sit for years and fire right back up like it was yesterday.

[rtcat600man]

Originally Posted by TastyBake

These two.


Is it beneficial?
Depends. There is less knock retard with 93 than with 87. Higher octane not only prevents knocking, it lowers KR from the PCM. If lowering KR is a requirement, then its beneficial. If you don't care, then no.

Is it required?
No. If you experience knocking, then get the car fixed.

Will I get more power?
Yes. How much, I dunno.

Will you notice?
Probably not. Just note KR is higher in higher revs.

Will I get better fuel economy from using high octane?
Yes. but there are bigger factors like your driving behavior that affect your mpg more than higher octane.

Will I get my money back from the mpg increase from using by using higher octane?
No.

Is using higher octane a waste of money?
Depends. For a daily driver that isn't driven hard, its a waste of money. If you take it to the track or really, really want all the power you can get stock, then go ahead.

Well, do you use higher octane?
Yes. I want to ensure I got all the passing power I can have on the highway. But I know I don't need to use 93.


If anyone disagrees with these points, reply.

I have no problem spending the extra few dollars to get the most I can get at all times. Less than a dollar per day for my use.

[RubyCamaro]

Originally Posted by SC2150

The knock sensors detect knock and pull timing before the human ear can hear it, so you should never here it. The Bosch ECU as pointed out has no high & low octaine tables, but it is constantly adjusting timing as detonation occurs and yes, the power is increased and economy slightly better with 93. Will it hurt the engine to run 87? Absolutely not....but the engine is 11.3:1 compression ratio....do a search on octain and compression ratio's. When running 87 you are rarely running at full timing advance, and that is inefficent. On the V8,s that have 10.5-10.7:1 CR, 93 is required. If you run 87, the PCM defaults to the low octain tables and the PCM further pulls timing as detonation is detected.



Correct that the ECU will adjust to the octaine run, and thats why I would never run 87....but I build these engines day in and day out and see them up close and personal from the inside...and I always want an engine to run at optimine...not just run OK.



That would be impossible...the A/F mixture would not be effected by the octaine. If you noticed it in the colder winter months, the black soot is from the cold start enrichment. Not noticeable in the summer months. But there is no physical way running 93 over 87 could cause black soot.

This^ I have been driving my V6 as daily driver, drag racing, weekend fun for long enough to have decided for myself. I could tell from the first tank of 93 top tier Shell gasoline, my baby was running much better. I never looked back. It is not worth the few cents I'd save to have my permagrin maker not run at max permagrin capacity. If cost is that much of an issue, fine, run the 87, no biggie. But for me.................once you go 93 you never go back.

[MagnumForceGB]

Nice thread I found on the issue.

http://www.camaro5.com/forums/showth...69#post2011169

[CDCNY]

what about non ethanol fuel? any benefit ?

[67 GTO]

I use 93 octane, car runs good.

[its a syn]

Highest octane for me, but mine is not a DD.