What sort of fuel additives are good for the 2.2 in a 2010 HHR? Will octane boost make any difference in the performance or economy? If I use an additive, how often should I use it? Every tank or every few tanks? Or is pouring additives in the gas tank just a waste of money on a lo-po engine like the 2.2?

 

I run a half a can of seafoam in all mine about every 6 months or so to help with moisture and to clean injectors.

 

I add a can of fuel injector cleaner every oil change , as for octane boost in a 2.2 not necessary!

 

Octane boosters, a waste of money really.

As for mine, they get a bottle of Chevron Techron II Fuel System/Injector Cleaner every 6,000 miles.

As for things that promise "Increased Economy" in a bottle, use your cash on something better like a new engine air filter, or an oil change.

Well maintained engines are happy engines, that combined with keeping your maintenance up to date, checking your tire pressures, and avoiding what I call "Mobile Storage Shed Syndrome" AKA carrying around a bunch of stuff you dont need...will give your HHR the ability to run happily and efficiently.

Even with GMPP Intakes, GMPP/Borla or Magnaflow exhausts(the '06 has a Magna-Snort system), and Trifecta Tunes...I'll get between 38 & 42 mpg on long highway runs. Around town/mixed driving produces an average of 22 to 25 mpg because I've got a heavy right foot.

And thats figured the old fashioned way, paper and pencil, the fuel mileage reading on the DIC is close...but not 100% accurate.

 

The only things that I carry in the car that weigh more than a few ounces are a tool box and a jump starter in case the battery goes dead. I have two package shelves and one of them fits in the stock location over the spare tire and under the carpet and another package shelf that stays in the upper position, creating a small "trunk" area that is hidden from prying eyes. When I want to haul bigger things, I just remove the second package shelf and put it on the floor.

 

I use 2 products depending on the season.

Spring and Summer I use Techron Complete Fuel System Cleaner every 7,000 miles.
That's 2 oil changes for me.
With a 2010 2.4L I do not use the Dexos or Synthetic oils.

In the Fall and Winter season I use Bell Mix-I-Go, Commercial Grade Gas and Ethanol Treatment using the same "add formula" as the Techron.

I also keep my fuel tank filled often especially in the Fall and Winter months to reduce condensation.

Once warm my engine idles absolutely smooth and consistent.

I Use Chevron or Costco 87 octane fuel religiously.

I have not done a Trifecta tune yet so 87 does the job fine.

Walmart has had the best prices on the Techron. I just bought some 10 0z.bottles that treat 15 gallons on a store mark down.

Silverfox

 

I put a can of Berryman's B12 Chemtool in all my vehicles every 6 months or so. The only reason I do is, back in the 80's, a friend of my dad's used it in a bike that he pulled out of the woods. The carb was full of crap, and the gaskets were all but shot. After riding it for several weeks with B12 in every tank, the carb looked like new, and it had basically restored the gaskets.

As far as performance, being a 2010, your 2.2 should be be the flex fuel LE8. Filling up with E85 is supposed to take it from 155hp and 150tq, to 160hp and 158tq. a bit of a boost, but not much, and you probably won't feel it, not to mention the decreased fuel economy. If you really want more power, I would go with a full exhaust(Header, downpipe, catback), and a tune(Trifecta, or HPtuners). The intakes on these cars are actually very well designed and you won't gain much if anything by switching it out. But, don't expect much, even with those mods. I knew a guy that had a fully built 2.2(pistons, cams, exhaust, etc) and he was still only making 187whp. While respectable, it's not even going to catch a stock LSJ Cobalt.

 

Seafoam in everything.

 

I wasn't implying that you suffer from "Mobile Storage Shed Syndrome" bugo, but lots of folks do.

It was either the AAA or the EPA that did a study a few years back that found an average of 100lbs of excess crap in the average American car.

 

I put Marvel Mystery Oil in 4 Oz. with a full tank of gas once a month.