Marcruger

Hi Lee, Indeed someone did do that with a remote thermometer. With the "wooly" worm tube in place, the stock intake air temp was about a degree or two warmer than outside air. With it off it was considerably higher. There is a post on this forum (or the "anathema" forum) that covers that.

BTW, I am running premium because I can feel the difference in my HHR. I bought it with 87 octane in it, and it seemed like forever before I burned it off. I've used 93 every since. I especially noticed that it felt more responsive.

Again, I am just one guy with one HHR, so I am no expert. I won't argue because I am not smart enough. The main thing is....Have Fun!

God Bless, Marc

sleeper

Marc-

I burn 93 also, with gas mileage being so good. I can justify the cost diff.
I'm sure when I got it, it was running regular. Cause it does run much-crisper
now..

Marcruger

Also, a ways back two guys did a long-term (like 6 months) test, alternating regular and premium in their HHR's. They recorded their mileage and fuel costs. It turned out that their cars were getting better mileage on premium, and it offset the extra cost to a degree. I read that before I bought my HHR, and decided to go ahead and run premium. That test is on one of the two HHR forums.

I also noted the GM recommends premium in the 2.4 liter cars, so that tells me they dial the timing back to prevent detonation if you put regular in a 2.4 liter. That could explain the lower gas mileage with regular, as a 2.4 would therefore run less efficient than intended.

Can I tell on Elvis? I don't know on mileage. Seems like I don't get the mileage numbers some do. However, with the power from the GMPP intake and premium gas, plus winter cold boosting horsepower, my foot has been pretty heavy. Weeeeeheeeeee. God Bless, Marc

peevlos

Well Said

Lee3333

Years ago there was someone on this forum that was an owner that became a vendor for HHR parts. He discovered that the Autolite plugs improved the performance (unknown why, since they are the same heat range but he ran tests and when I put them in my car it the car did burnouts with less throttle). He also started using, and selling, octane booster tablets. They really helped the way the car felt, but he later retracted when he discovered that they were damaging something in the engine (I forgot what exactly). The point being that the engine computer really does change settings based on the fuel octane.

retrolled

LEE3333...... Very good point on the stagnant air while dyno'd.

mrarff

I have a K&N airbox on my 2.4. I bought some foam/adhesive backed foil water pipe insulation from Home Depot(less than $4) I wound it around the "wooly worm"(securing it with cable ties) and also applied it to the inside if the K&N box. I have a ScanDisk monitor plugged into the OBDII, and it shows the intake temp for the throttle body. It will be no more than 6 degrees warmer than the DIC outside temp reading. If you have time on your hands and are bored, try it.

jay loukakis

When I first got my HHR I changed to the K&N in the stock air box, then bought the CGS, then I modefied the CGS cut and welded and used an Edelbrok 10 inch round filter with a paper filter it is near the stock oprning in the fender also cut a section of the plastic next to the radiator for more cold air, now I get torque steer and chirp the tires and better gas mileage , but sometimes I get a code saying it is leen fuel is it because of more air than stock I never got that message with the stock with the K&N or the CGS it only come on once inawhile regardless of speed no change in performance or gas mileage?

mrarff

I get better milage (1.5/gal) and loads of torque steer. I NEVER have "oiled" the filter medium, and when I saw how much the "pre-filters" cost, I made my own. The wife did question me about the pantyhose in my toolbox though.

fincsher

I just noticed the premium.. Is that the gas of the HHR? I am confused with that.