bigjacksauto, I think if someone dyno'd it, it would only be single digits difference... I notice a bigger pickup with my air cleaner lid on during a hot day...

 

According to my butt dyno
my 55 Chevy car runs much better with the straight ethanol free gas
Just tried it yesterday. 1 hour each way to a car show
Ended up with a top fifty out of 701 cars
Made my sons day and mine
As far as with air cleaner lid off vs on
The ss definitely will loose power at full throttle at operating temp with lid off
You can only compress hot air so much even if it is cooled.afterwards
I am guessing that If I had an injected computer controlled motor in the 55 I would
not notice as much of a difference with the ethanol free gas

 

We run A 91 octane E85 Blend, a 1:1 ratio. With the tune for it and have plenty of power and still get 30 mpg in the HHR SS. But in the TBSS 91 octane ethanol free gives me about 1.5 more mpg than 93 octane with ethanol.

 

Now you guys are really starting to scary me...

We're dealing with a forced induction engine here.
You always want to put the higher octane fuel in it.

If you have 93, use 93, plain & simple.
Your engine will love you for it.
Your ring lands will love you for it.

Did I mention the we have a forced induction engine ?

If your only keeping your wagon for a few years, & don't
give a crap about your engine or performance, go with less octane,
& less power...

If anyone mentions fuel mileage again, trade your wagon
in for a Yugo, you don't need a high performance car...

Of course your going to get less mileage, with any Ethanol content.
Ethanol has 1/3 less BTU content, plain & simple.
If your not tuning it, don't mess with it, use 93, PERIOD.

Ethanol + forced induction + tune = a torque monster...
Just a 50/50 mix = 30hp minimum increase in our wagons, with a HUGE
increase of torque, 'under-the-curve'. and better throttle response.
I'ts hands down, the BEST mod for our wagons...
1. More power
2. More torque
3. Better throttle response
4. Longer engine life
5. Smoother engine
6. Zero knock
7. More ear-to-ear smiles
8. Stronger arm muscles, holding the steering wheel in place.
9. The best thing since sliced-bread

 

X2 Amazing power diffrence. I'm going to Have My TBSS tune for it also if it is capable, and economy is not an issue there. I didn't get SS for economy. I was very surprised in the HHR SS still getting 30 mpg with that much power.

 

I guess I was more or less questioning on a stock hhr ss tune about the pure gas vs the watered down ethanol

Now of course More octane certainly does not make more hp all he time

Example I run a 700 plus horse street car with a roots blower
110 octane is as good as it gets hp wise.
anything more and I will loose power.

I am assuming that is the same reason why when running a 50/50 mix of e85 you are running a low octane 93 gasoline instead of 110 mixed in?
I am still learning on the turbos

 

I talked to one of the reps for the gas station/stores in our area At the Syracuse nationals this weekend.
That are now selling ethanol free gas.
They use to sell 93 octane which contained 10% ethanol.
Now they sell 91 octane ethanol free.
The difference simply is that the 93 was 91 octane pure gas with 10% ethanol added to bring the octane rating up.
So with a gm Turbo upgrade I am assuming that the ethanol blend would make more power.
anyone know what octane the gm Turbo upgrade is optimized for?
2005Hhrauto I believe at one point you mentioned that.100 octane unleaded would be best?

 

Round here I run Chevron 94 octane 0% ethanol



I see 21 mpg 100% city, 35 mpg highway (and it was a hilly highway)

 

Its been years since we had 94 octane in Central NY