Has anyone with an automatic HHR SS installed the GM performance upgrade kit? If so how did it affect driveability and gas mileage?

 

I have the manual, but from what I have read is that you will gain gobs of power and bring the HP on par with the manuals.
Fuel mileage usually decreases not because the engine is less efficient, but because the driver can't keep their foot out of the throttle.
Also, you will have this silly grin on your face for some time....

 

The Stage 1 is amazing. Totally different car with it installed.

General driveability is pretty much the same - no major difference until you stomp on it. Performance in the snow may be an issue (but probably not for you) but nothing that would make me regret the upgrade.

I have a short commute so I'm not too concerned about mileage, but from what others have said you should get a marginal improvement. You will have to use premium fuel though, where with the stock engine premium is optional.

 

Driveabilty is a fun factor X 10 over stock, along with 28 mpg, for me on a open road 22 mile work commute at mostly 60+ mph. It is worth the $.

 

if only I had a dealer I trusted to do the upgrade - they couldn't even get the brake fix correct

 

Get the upgrade. If you want to see a dyno run, check out what I put in the gallery here too (granted I have the Hahn turboback exhaust too). It's one of those mods that is a no-brainer. Factory backed and warrantied, great hp to dollar value, and did I mention it's warrantied??? DO IT!

Later
Allex

 

Barton Birks Chevrolet in Newburgh NY has done a bunch of them.
(I think it was) 87Silver got his done there after he heard they had done a few.
He said they did a great job so I drove the 175 miles there to get mine done.
$200 as quoted, outa there by 10:30 AM and a good professional job.
They soldered the connectors (as requested) instead of using the clips provided for no extra charge.
Worth the drive.

BTW - Orange County Choppers is about a mile up the street for a photoshoot and gifts

 

I have the auto and it drives just fine. If you get the upgrade just hold on to the steering wheel at take off.

I comute about 40 miles around trip and get an average of 26 to 27 mpg if I keep it under 70 which is very hard to do. However at 60'ish I can get over 30mpg.
Good Luck

 

Damn i only get 18 miles to a gallon haha. But i have a couple other mods then just the stage kit. My gas mileage doesnt bug me though i love the car

 

My gas mileage didn't get affected at all when you drive normal. I do both city and hwy driving to get to work.