4:10s suck

Dans Denali · June 25, 2006

I just had my daughter follow me 170 miles driving the wifes 03 Yukon Denali XL and it got 2 mpg better than my 02 sierra Denali, only difference is the gear ratio! I got 15.7 and she got 17.6 driving 60-75mph.

Dan

Hecktorx · June 25, 2006

Was she right behind you the whole time? She may have got better milage because you were breaking the wind for her the whole time.

pwall · June 25, 2006

Wouldn't it be normal that the 3.73 got better gas mileage than the 4.10 ?

Dans Denali · June 25, 2006

No she wasn't close and yes I would expect gears to make a diference, but 2 mpg? And the Yukon is #300 heavier! Must be drag-wind resistance, I had my actory tonneau cover on. My engine turns 2200 @70, probably too many revs for economy. I think hers runs 1800@70.

Dan

asilverblazer · June 25, 2006

Put a 5000lb trailer behind each, it's what we buy big a$$ trucks for anyways, and see how the mileage compares.

pm26 · June 26, 2006

No she wasn't close and yes I would expect gears to make a diference, but 2 mpg? And the Yukon is #300 heavier! Must be drag-wind resistance, I had my actory tonneau cover on. My engine turns 2200 @70, probably too many revs for economy. I think hers runs 1800@70.

Dan

<{POST_SNAPBACK}>

1800 vs 2200 RPM ? That's about 20% difference. If this were true, and the truck doing 2200 RPM has 4.10 gears, then the truck doing approximately 1800 RPM would have to have 3.42 gears. 2 MPG difference is about right between these two gear ratios.

diverlloyd · June 26, 2006

No she wasn't close and yes I would expect gears to make a diference, but 2 mpg? And the Yukon is #300 heavier! Must be drag-wind resistance, I had my actory tonneau cover on. My engine turns 2200 @70, probably too many revs for economy. I think hers runs 1800@70.

Dan

<{POST_SNAPBACK}>

1800 vs 2200 RPM ? That's about 20% difference. If this were true, and the truck doing 2200 RPM has 4.10 gears, then the truck doing approximately 1800 RPM would have to have 3.42 gears. 2 MPG difference is about right between these two gear ratios.

<{POST_SNAPBACK}>

I agree. Once again we have someone who has a TRUCK, but wants a) high mileage and/or b) a car-like ride. With these demands, I'm not surprised by some of the wierd engineering decisions coming out of GM. I have 4.10s on my truck and I love the way my truck pulls and handles but then again I use my truck as a truck!

I-H8-4Ds · June 26, 2006

It's unbelievable what a difference the axle ratio makes. You can have good fuel economy with your 3.23 axle, or you can do a decent job towing something over 2000 lbs. with your 4.10, but you can never get both.

pm26 · June 26, 2006

It's unbelievable what a difference the axle ratio makes. You can have good fuel economy with your 3.23 axle, or you can do a decent job towing something over 2000 lbs. with your 4.10, but you can never get both.

<{POST_SNAPBACK}>

That's why I opted for 3.73 gears on my Z71 . They are a good compromise between fuel economy and performance/towing ability.

Dans Denali · June 26, 2006

It's unbelievable what a difference the axle ratio makes. You can have good fuel economy with your 3.23 axle, or you can do a decent job towing something over 2000 lbs. with your 4.10, but you can never get both.

<{POST_SNAPBACK}>

That's why I opted for 3.73 gears on my Z71 . They are a good compromise between fuel economy and performance/towing ability.

<{POST_SNAPBACK}>

I think 3.50 or so would give you good mileage and give the ability to tow in drive.

Dan

SoCalChris · June 26, 2006

you were breaking the wind for her the whole time.

<{POST_SNAPBACK}>

If I was breaking wind for 170 miles, my mileage would be the last thing I'd be worrying about. I'd probably be looking for a new seat to replace the one I had been in, or at least a good air freshener. I hope you've got dark seats.

Steves95Sierra · June 26, 2006

<lmao>

gmcjoe · June 27, 2006

Wouldn't it be normal that the 3.73 got better gas mileage than the 4.10 ?

<{POST_SNAPBACK}>

Yep

mmmikkke · June 27, 2006

No she wasn't close and yes I would expect gears to make a diference, but 2 mpg? And the Yukon is #300 heavier! Must be drag-wind resistance, I had my actory tonneau cover on. My engine turns 2200 @70, probably too many revs for economy. I think hers runs 1800@70.

Dan

<{POST_SNAPBACK}>

1800 vs 2200 RPM ? That's about 20% difference. If this were true, and the truck doing 2200 RPM has 4.10 gears, then the truck doing approximately 1800 RPM would have to have 3.42 gears. 2 MPG difference is about right between these two gear ratios.

<{POST_SNAPBACK}>

I agree...

<{POST_SNAPBACK}>

I had 4.56:1 gears in my 95 k3500 and it got 13-14 mpg on the highway, no different than others with k2500's with 4.10 or 3.73 gears. It definitely didn't suffer by 2 mpg. It depends on many other things. The yukon has a better aerodynamic signature than the truck, even with its tannau cover.

C & A s Dad · June 29, 2006

My wife's '02 Yukon XL 1500 5.3L is averaging 18.3 with 4.10s unless I have our 6,500lb camper behind it. Her driving is mostly short rural trips with no more than 20 to 30 highway miles at one time. She also drives in a very conservative way.

I have added a True Flow CAI which moved my mpg from an average of 17.5 to 18.3 using 6 tanks before and 6 tanks after as my aveage. In addition, I run 37 PSI in the tires and have Amsoil syn in the engine and trans along with GM syn in the rear axle.

IMO, 4.10s can actually help a vehicle this size get better mileage than higher gears. It all depends on driving habits and the terrain you drive on.