CaptainObvious

Formally known as RV6Junkie
Damn Yankees
LIFETIME SPONSOR
Jan 8, 2000
3,331
1
I'm looking into buying a Silverado LS 1500 (5.3l, ext cab, 4x4, 8' box). One of the options for towing is the 4.10 gear set. I'm concerned that that the gas mileage, already poor at 18 mpg, will be much worse.

Are 4.10's really required to load up a few bikes, haul a 8' trailer while having 5 on board? Can someone with the 4.10 rear give me your highway mileage?

Thanks
 
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XRpredator

AssClown SuperPowers
Damn Yankees
Aug 2, 2000
13,510
19
I get by with 3.73's behind a 350 in my '92 shortbox. 4.10's will for sure dog your gas mileage, but you won't be doin' much shifting down.
 

Rodzilla

LIFETIME SPONSOR
Jul 21, 1999
615
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I have a '99 with the 5.7 liter (the 5.3 here at work goes every bit as well)

And I have the 3.73's

I pull a 13 ft pop up camper (about 1500 lbs) with two bikes in the back, gear two dogs and a pregnant wife and can still pull the Eisnhower Tunnel (6% grade at 11k feet and 2+ miles long) at 60 miles per hour.

It does down shift more than I want, but here in Colorado we do have a few "hills" to contend with.

I'd say if you are not hauling anything big, the 3.73's will be fine.

Rod
 

Highbeam

~SPONSOR~
Jun 13, 2001
665
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I have a 98 k1500 with the 3.73 and even though I only tow a light load I wish I had the 4.10s. I just finished a long drive, about 2000 miles not towing, and I made some observations. I have the z71 package with 265/75 tires and the same 4l60e transmission your truck will have. Your truck will have a tall overdrive gear. The manual recommends towing and driving in overdrive unless your transmission hunts. 80 mph is only turning about 2200 rpm, this is in a pretty good power range for my 5.7 liter engine, 3200 is the torque peak. Your 5.3 will need to rev even higher for power. Through CA when I was cruising at 70 I would have to downshift at many hills just to keep up speed, I could take bigger hills in OD at 80 mph through WA since the revs were a little higher. If I had the 4.10s I could have cruised at 70 and had more punch for the hills. What I'm getting at is that the 4.10s will give you more power at highway speeds by letting the engine rev closer to the power peak. Mileage didn't really change between 70 and 80mph, we drive bricks.

Another issue is that I, like most red blooded american 4x4 owners, intend to put tires at least one size larger on which will effectively lower my rear end ratio for even less highway power. Another reason for the 4.10s.

I recommend the 4.10s for you and that engine/tranny combo. 18 mpg is great for a v8 full size truck, just look at what that hemi gets.
 
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