As the cold (relative, since I'm in central TX, cold is anything below 60 degrees) temps here in Austin I've been noticing how much the cold air effects my MPG on my '08 LS 2.2L manual.
For instance:
On my way to work in the afternoons the ambient temps are ranging from 65-75 degrees
and I average around 33-36 on the highway (Most of my commute is highway) at 60-70mph.
However on the way back home, around 10pm, it's much colder ambient temps...usually around 40 degrees.
I can barely average 30 mpg on the way home going 60mph.
I realize my tire psi's are slightly lower in the colder temps, but they're not much.
In the heat, the tires are at 35-37psi...in the cold they're at about 32-35. I hypermile as much as possible.
I realize this is still normal for the HHR, but I can' just leave something alone if there's a possibility to improve it.
So here's my idea:
Move the stock air intake hose (the flexible one) from the hole in the fender to directly below where it attaches to the airbox.
I ran it down the fender well as to get the warmer air coming off the exhaust manifold.
I realize that warmer air is worse for performance but it's better for MPG. The colder, denser air
requires more fuel to atomize correctly at 14.7:1....conversely, warmer air is thinner and requires
less fuel to reach the stoichiometric goal. The trade off is that the less fuel, the worse performance....but it's an HHR.
Like I was telling my wife, my HHR is my mileage hot rod. I want my go-fast cars to go as fast as possible....
I want my HHR to get the best mileage possible.
I won't get to test it out until Monday, but what are y'alls thoughts?
Here's where the stock intake hose went:
Here's where I moved it to:
