Chevrolet Cruze Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
82 Posts
Discussion Starter · #1 · (Edited)
Ok as promised i took another cruze out for comparison and had a friend of mine drive it, we did some highway runs but they were disaster i couldnt record and race at the same time, lol. I was going on 2 and would still fall behind he had it in 3rd gear tap shifting it. I still ended up pulling on him 1 1/2-2 cars from 50-90mph.

The only vid i have was on the street we went off the line he was first on the throttle so he got a bit of a jump on me till i got into my boost as well and started to pull not by much but pulled slightly i think. Both are auto's, both had just drivers no passengers and we both did left foot on brake, right foot on gas build rpms and boost and let off the brake.

 

·
Registered
Joined
·
104 Posts
Was he using premium gas too? It isn't really a fair comparison of the stock tune unless he's using the same octane you are.
 

·
Premium Member
Joined
·
333 Posts
Was he using premium gas too? It isn't really a fair comparison of the stock tune unless he's using the same octane you are.

The octane rating isn't going to make a bit of difference in overall performance, maybe a bit for mileage but that'll be comparing tenths of MPG's
 

·
Registered
Joined
·
104 Posts
The octane rating isn't going to make a bit of difference in overall performance, maybe a bit for mileage but that'll be comparing tenths of MPG's
Can you explain that one to me? With higher octane, the engine should be closer to MBT. This engine is clearly knock limited, so adding more octane should result in more spark advance and let it sit in an overall more aggressive portion of the cal. That should get more power/torque.

That is how I understand it atleast.
 

·
Premium Member
Joined
·
333 Posts
You are correct. Although, fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power. With how small of an engine we have, it won't really make a lick of difference. Your maybe talking in the realm of a couple to maybe 5 HP at most. Especially since the computer is probably only going to let it advance so much (unless it's tuned obviously).

In a larger engine where there is a ton more heat produced per cylinder cycle, it'll make a larger impact having an octane rating suitable to avoid detonation.
 

·
Registered
Joined
·
665 Posts
The octane rating isn't going to make a bit of difference in overall performance, maybe a bit for mileage but that'll be comparing tenths of MPG's
Your completely wrong, see the thread about this car and octane in the summer as confirmed by the head GM engineer for this vehicle.
 

·
Premium Member
Joined
·
333 Posts
You cant account for every variable in every situation, and that thread is talking about high temp situations which is not an everyday driving condition. Which you can say the same thing about higher altitudes not producing the same HP as well, so what about that?

There will always be different circumstances where one will be slightly better than the other, but as a GENERAL assumption, for an average day, it won't make that big of a difference if any.
 

·
Premium Member
Joined
·
333 Posts
Oh and I might add that the higher octane helps more when the car has been sitting in the sun and just started. It'll take a bit of driving to cool down the Intercooler to get intake temps down, which is the biggest cause of loss of power in that situation.
 
1 - 11 of 11 Posts
Top