2008 2LT with 2.4. 27,000 miles.

I am averaging 28.5 according to the DIC. It's about 75% highway driving, but about 75% of my highway driving is in stop-n-go rush hour.

I drive it light and do a modified pulse and glide wherever I can and coast down hills. Even when I do have to stomp on it to pass, etc., the DIC still shows I'm getting 20-21 inst.

Highway steady speed I can hit high 30's.

 

I live in a pretty hilly city, so my city mileage is just over 21, but when I had to work about an hour away, thru flatland, I averaged about 29 at 70mph. I think I should be able to squeeze a couple more mpg overall, and thats why im on this forum, any tips? 2.4 totally stock automatic

 

A road trip yesterday from Florida to Manning, SC I averaged 32.6 mpg (calculated) 484 miles and 14.82 gallons..2.4 auto, just cruising at the speed limit. My DIC says 31.7.

 

my tires are wearing evenly on the rear , and still wearing on outside of treads on the front. i have seen overinflation cause a tire to wear more on the center of the tread , but never on outside. wear on the outside of the tread on the front tires is fairly normal for most vehicles. that is why it is recomended to rotate. my hhr handled worse in all conditions with lower pressure. the tires would even spin more(lose traction) from a dead stop when i had the lower pressure. they will hardly ever break traction now when i try to with the higher pressure . tire companies test their tires , it is their business to know what pressure is good for their tires. when profesionals race , they are always adjusting the pressure. i suggest the same on the street. also a tire that does well on 1 vehicle may not do well at all on anouther vehicle. it is test and retest to find what works the best . what you are saying may be true for some tires, but it has not been true for the firerstone gtas that came on my 08 hhr. i have 60,000 miles on them , i haven't rotated them in the last 25,000 , the wear bars are starting to show , but the rears are absoluly wearing perfectly even. i think they were only rated for 40,000.

 

Well I have 11500 miles now and I'm getting 29.5mpg avg on the last 2 tanks. That is fantastic. If I try I can get about 2-4 better.

 

I'm still on the road, probably 95% highway and have been getting 32+ mpg using cruise control and have covered a little over 3000 miles with the average speed of 54 mph. However I've only seen two days of sun and have been driving in the rain. I made it up to Freeport Maine and got to see snow and cold weather. The heater works.

 

Just wondering, does rain affect MPG? Only reason I ask was it rained my entire trip last weekend, and wondered if that affected anything.

 

Yes, of course rain increaser fuel consumption. I'm guessing here and some effects are miniscule

1. Wet road to tire contact means more resistance,

2. More drag from a wet air/body surface,

3. Impact of rain drops slowing you down,

4. Heavier vehicle when it is wet and

5. Electrical load from wipers.

And if it is cold as well as wet, we could add some more.

.... any more for wet conditions, no matter how trivial.

 

Finally back to Florida after a 4000+ mile road trip that took me as far north as Freeport Me. Average speed 54 mph and 33.6 mpg. Probably 95% highway with cruise. Some segments a lower pace at 55 mph and was getting nearly 36 mpg. As I got back to the heat of Florida, with the AC on, it dropped my mileage down to 30 mpg. Also those segments were at 75+ mph.

The 2.4 auto was using 87 octane.. Many days of driving in the rain.

 

2.4 w/5spd @ 40,000miles using 87

Just drove to see family and got 32mpg highway. Was cruising @ 65-70mph the whole way

My city is about 24-26 depending on when I shift

Having neglected tire maintenace for a while, my tire pressure was low. After having them rotated and properly inflated, these are the numbers I got. Before it was closer to 22/27 (about a 2-3mpg difference overall).