MPG versus Final Drive Gear Ratio
Member
Joined: 04-29-2010
Posts: 85
From: Michigan
One thing to remember though, a lower gear ratio doesn't always equal better fuel economy. There are a lot of factors involved including driving style and conditions. As an example, I have a Trailblazer with 4.10 gears, and on long trips at 72 mph, I get 22 mpg. My dad has a Trailblazer with 3.42 gears, and at that speed, it struggles to get 21 mpg. My engine seems to be in the sweet spot at that speed and RPM, while his struggles at that speed.
My SS 5 speed has a 4.05 final drive ration BTW. On the way up north this past weekend driving mostly freeway at 80-85, we averaged 28 mpg. On the way back on mostly 2 lanes at 60, the avg was 31.4.
My SS 5 speed has a 4.05 final drive ration BTW. On the way up north this past weekend driving mostly freeway at 80-85, we averaged 28 mpg. On the way back on mostly 2 lanes at 60, the avg was 31.4.
Senior Member
Joined: 03-19-2009
Posts: 296
From: Connecticut
One thing to remember though, a lower gear ratio doesn't always equal better fuel economy. There are a lot of factors involved including driving style and conditions. As an example, I have a Trailblazer with 4.10 gears, and on long trips at 72 mph, I get 22 mpg. My dad has a Trailblazer with 3.42 gears, and at that speed, it struggles to get 21 mpg. My engine seems to be in the sweet spot at that speed and RPM, while his struggles at that speed.
My SS 5 speed has a 4.05 final drive ration BTW. On the way up north this past weekend driving mostly freeway at 80-85, we averaged 28 mpg. On the way back on mostly 2 lanes at 60, the avg was 31.4.
My SS 5 speed has a 4.05 final drive ration BTW. On the way up north this past weekend driving mostly freeway at 80-85, we averaged 28 mpg. On the way back on mostly 2 lanes at 60, the avg was 31.4.
With a Manual car, you can keep the RPMS down and skip gears with drastically helps gas milage.
A stock tuned Auto matic has it's quirks and most times will not upshift unless its north of 3k rpms. Thats where the fuel gets wasted the most.
Platinum Member
Joined: 01-09-2007
Posts: 16,081
From: SE USA
Senior Member
Joined: 02-06-2010
Posts: 580
From: Shreveport, LA
specifics please
I believe the original poster got it backwards. Lower final drive ratio gives higher, "stiffer" gears and lower RPMs, and hence better mileage. I also believe that the final drive ratio on the manual non-SS was lowered in more recent HHRs to improve mileage.
Member
Joined: 01-22-2010
Posts: 33
From: Canada
computer fives an Avg speed of 35-40 mph, fuel mileage usually around 23 MPG.
I don't drive it like I stole it. When trying really hard to get the best mileage I can (slow accel, little braking, set cruise as often as possible) , I can't ever seem to top 27-28. highway speeds @ 55-65 mph.
That said, its not terrible. Better than the Honda Accord it replaced, surprisingly... But I thought I'd be able to squeeze 30 out of it, like some forum members seem to.
Platinum Member
Joined: 01-09-2007
Posts: 16,081
From: SE USA
I don't seem to get great mileage. 06 2.4L, 5spd.
computer fives an Avg speed of 35-40 mph, fuel mileage usually around 23 MPG.
I don't drive it like I stole it. When trying really hard to get the best mileage I can (slow accel, little braking, set cruise as often as possible) , I can't ever seem to top 27-28. highway speeds @ 55-65 mph.
That said, its not terrible. Better than the Honda Accord it replaced, surprisingly... But I thought I'd be able to squeeze 30 out of it, like some forum members seem to.
computer fives an Avg speed of 35-40 mph, fuel mileage usually around 23 MPG.
I don't drive it like I stole it. When trying really hard to get the best mileage I can (slow accel, little braking, set cruise as often as possible) , I can't ever seem to top 27-28. highway speeds @ 55-65 mph.
That said, its not terrible. Better than the Honda Accord it replaced, surprisingly... But I thought I'd be able to squeeze 30 out of it, like some forum members seem to.