What kind of gas are you filling up with in your '10 Camaro?

[Nova65]

regular, if you wanted to put in premium you should get the ss

[knowitman]

Originally Posted by SSOOCH

What I don't get is the owners manual for my HHR SS states to only use 91 octane or higher on it's 2.0L Eco-Tec. So why do they not require it in the 3.6L, 44 more horse power V6 that's in the LT Camaro? Is it because the HHR SS is turbo?

I use 91 in the HHR SS & my SS/RS Camaro!

I take it you don't fully understand what the octane rating on fuel really means. I will try to give the basic rundown.

When exposed the to the high temperatures and pressures of the inside of a cylinder, an air/fuel mixture is prone to explode. The amount of energy it takes to cause this to happens is called the activation energy. The octane rating of fuel is basically a rating of the activation energy of the fuel. The higher the number, the harder it is to get the fuel to combust. I could go into more detail about how it is actually a comparison of the activation energy of pure iso-octane and that higher octane fuel actually contains less potential energy then lower octane fuel, but I'll save that discussion for another day. Now back to activation energies and octane ratings. Higher octane fuel has a higher activation energy, meaning it is harder to get 93 octane fuel to combust then 87 octane fuel. How does this apply to your engine? In ideal conditions, you want the fuel to combust only when the spark plug sparks. If it sparks prematurely, you aren't able to extract all of the potential energy from the fuel, you will get "engine knock" and you could actually damage the engine because the air/fuel mixture could be igniting while the piston is still on the up stroke and you have the the piston pushing into the expanding gasses rather then the expanding gasses pushing into the piston. Now onto compression ratios. Because of reasons far more advanced then I want to go into, the higher compression you can run, the more energy you can extract from the fuel. This means you get more power out of the same amount of fuel and the engine just overall runs more efficiently. The downside is that running higher compression also exposes the fuel to higher temps and pressure making the chance of premature detonation higher. This is why you need higher octane fuel. The fuel is able to withstand these more extreme conditions and not detonate until the spark plug sparks. There are other factors such as timing which is when the spark plug sparks. If a lower octane fuel is used, the spark plug is going to have to spark earlier to prevent the engine knock, and this sacrifices efficiency and power. Now onto turbos, even though turbo engines actually run at a lower compression ratio, the engine, by nature of it having forced induction, is going to run at higher pressures. This means that a higher octane fuel is needed for the engine to run at it's best.

Where does the DI V6, LS3, and Turbo Ecotec fall into this discussion. Because of the direct injection on the V6, the fuel can be injected into the cylinder after the air. This means that the engine can run at a higher pressure and not risk detonating the fuel that isn't present in the cylinder. This helps it run on lower octane fuel while maintaining a higher compression ratio. This is how GM designed it to run, and you will get little to no benefit from running higher octane. In the LS3, there is no direct injection. This means the fuel enters the cylinder with the air. This is also a high compression engine because of the performance nature of the engine. This means that a higher octane fuel is recommended, but a lower octane fuel can be used at the expense of less timing and lower power and efficiency. The Ecotec engine, being a turbo engine runs at higher pressures, and a higher octane fuel is highly recommended. I hope I haven't bored/confused you with this post and that you do learn something from it.

On another note, running too high of an octane for your engine can damage it as well. If an engine is designed for 87 octane fuel, running 93 might not give you an benefit. What could happen is an incomplete burn because of the fuel having a higher activation energy then what the engine was designed for. This results in more emmissions, lower efficiency, and less power.

[tjd24]

First tanks were 87 then I switched to 89 Sunoco and I feel and hear a difference. Now at 1,900 miles and 5 tanks on 89 - the start is smoother, idle as well and sounds better, and merging is without hesitation (whereas on 87 it felt a bit sluggish ).

So I'm A-OK using 89 and do not intend to go lower or higher.

[Bbrock25]

I've tried this in my 06 chevy truck 87 octane vs 91 octane. You get a little better gas mileage with the 91 vs the 87 but you pay more for it. Basically it evens out, spend more get a few more miles on a tank. As far as mileage goes in the end it evens out, but for your engine the 91/93 w/e you have in your area is better for it.

Not to mention the good gas is only .20 cents more per gallon. The car holds 19, if you coast in the station and on empty it will cost $3.80 more (on the total price) of that of the cheap gas.
Say its 2.30 for reg. and 2.50 for supreme Reg fill up = 43.70 Supreme = 47.50 total of $3.80 difference.

In the long run I think it pays off, better running engine, and a bit better gas mileage/performance.

Just my .02

[LightningSS]

Originally Posted by Bbrock25

I've tried this in my 06 chevy truck 87 octane vs 91 octane. You get a little better gas mileage with the 91 vs the 87 but you pay more for it. Basically it evens out, spend more get a few more miles on a tank. As far as mileage goes in the end it evens out, but for your engine the 91/93 w/e you have in your area is better for it.

Not to mention the good gas is only .20 cents more per gallon. The car holds 19, if you coast in the station and on empty it will cost $3.80 more (on the total price) of that of the cheap gas.
Say its 2.30 for reg. and 2.50 for supreme Reg fill up = 43.70 Supreme = 47.50 total of $3.80 difference.

In the long run I think it pays off, better running engine, and a bit better gas mileage/performance.

Just my .02

$3.80, and I can't remember the last time I had to wait in line at a Cheveron....

[PolishMike]

I use 91 (highest in California) at Chevron because I have a company gas card. I would probably still use it even if I had to pay for it.

[Spectre-2112]

I'm running 91 octane in my 2SS/RS, and will continue to get the highest octane. Better to have the engine operate at optimum perfomance.

[biker2381]

I want to buy the v6 LT just so I can use 87 octane. It will be an everyday driver.
I figure the v8 burns more fuel, AND it requires hi test which is $.20 more per gallon

[sigma_1966]

So if you have a 2LT and it recommends 87 but your using 91 or 94 is it going to be a proble ?

I dont mind paying an extra $4.00 for better gas mileage and a better performance. can it hurt the engine ?

[PolishMike]

Originally Posted by sigma_1966

So if you have a 2LT and it recommends 87 but your using 91 or 94 is it going to be a proble ?

I dont mind paying an extra $4.00 for better gas mileage and a better performance. can it hurt the engine ?

Your not going to see much, if ANY gas mileage or performance. If the car is tuned for 87 use 87.

If you get your car tuned then use whatever gas the tuner tuned it to.

[slick rick]

91 in my SS

[DMAX]

sunoco ultra

[JohnnyBfromPeoria]

Whatever my neighbor puts in his unlocked truck.

Kidding.

John B.

["prima"Donna]

Originally Posted by Sir Nuke

I am and will be using regular, just likes designed for, anything more is a waste. I have another GM, and it sports the same engine, the 3.6 DI V6, it runs GREAT. putting plus or superme in will only drain you wallet faster, not give you better performaqnce.

AGREED!!!