Is it worth changing gears for better MPG's???

**DA BIG ONE** · 08-10-2006, 03:47

Originally Posted by TurboDiverArt

Update. I just pulled the steel rims from the truck. Unfortunately the weight of the steel rim and 245/75-16 is right at 72lbs. If my calculations of what the H2 rim and tire will weigh (265/70-17), it's the about the same. H2 rim weighs 30 lbs and the tire is 41 so they weigh the same. Bummer for finding a lighter wheel combination, at least it'll look good!

Art.

How about update..........

**TurboDiverArt** · 08-21-2006, 03:43

Originally Posted by DA BIG ONE

How about update..........

Sorry about that, been off-line for little bit. Towing out to Salem seemed to be good. I got 15 MPG, one more MPG than I did last year. Average speed about 70 MPH. Coming back I was tired and had a friend drive. He doesn't use cruise control so not a fair comparison.

Around town driving it seems to be about the same. I have not taken the truck on a long highway non-towing trip yet.

Art.

**Shikaroka** · 08-23-2006, 07:56

I apologize if this has been covered, but I have a question.

If I want to put in a set of 342s in my 96 Suburban K2500, where should I look? What other trucks can I use the parts from?

Thanks!
Todd

**Shikaroka** · 08-27-2006, 08:18

I just swapped out the stock 16" steel wheels off my 96 Suburban, for a set of aluminum 16" wheels from the newer trucks.
My stock steelies (w/ 245/75/16 tires) weighed about 82 lbs. The aluminum wheels (w/ same size tires) weigh about 54 lbs. That's a difference of 28 lbs. which is pretty substantial when you are talking about unsprung weight.
I can already tell a difference. The truck is certainly peppier. I suspect I will get a little better MPG too, at least I hope so.

Also, since I have the 14 bolt, 10.5" rear end, is 373 the lowest number gear set I can get?
I think I'll be rebuilding my rear end soon.

**DmaxMaverick** · 08-27-2006, 11:08

Originally Posted by Shikaroka

I just swapped out the stock 16" steel wheels off my 96 Suburban, for a set of aluminum 16" wheels from the newer trucks.
My stock steelies (w/ 245/75/16 tires) weighed about 82 lbs. The aluminum wheels (w/ same size tires) weigh about 54 lbs. That's a difference of 28 lbs. which is pretty substantial when you are talking about unsprung weight.
I can already tell a difference. The truck is certainly peppier. I suspect I will get a little better MPG too, at least I hope so.

Also, since I have the 14 bolt, 10.5" rear end, is 373 the lowest number gear set I can get?
I think I'll be rebuilding my rear end soon.

You can get aftermarket R&P's. Randy's Ring & Pinion has gears down to 3.21 for the 14 bolt.

Since your truck is a 4x4, you'll need to do the front, as well.

**Shikaroka** · 08-28-2006, 07:37

Thanks!
But, I think 321 might be too low. They don't have anything listed between 321 and 373.
How do I know what gear set I need for the front? Would it be the same as the rear, a 10.5"?

Please forgive my ignorance.
I have been working on cars for over 15 years, but I am new to the 4x4 game.

**DmaxMaverick** · 08-28-2006, 08:55

Originally Posted by Shikaroka

Thanks!
But, I think 321 might be too low. They don't have anything listed between 321 and 373.
How do I know what gear set I need for the front? Would it be the same as the rear, a 10.5"?

Please forgive my ignorance.
I have been working on cars for over 15 years, but I am new to the 4x4 game.

Give them a call. Tell them what you have, and what you want to do with it. They have options not listed on the website. A 3.42 (common ratio) may be available, but you asked about ratios higher (lower #) than 3.73. There wouldn't be a significant difference between 3.42 and 3.21, and you can adjust final drive with tire size, as well. If you stay with stock tire size and don't tow heavy or frequently, 3.21 may be ideal. Some rigs are as high as 3.08 and loving it.

**Shikaroka** · 08-28-2006, 10:28

Cool, thanks for the info!

**JohnC** · 08-28-2006, 13:42

3.42 was available from the factory, so it should be available in the aftermarket, too.

**6.5 Detroit Diesel** · 11-15-2006, 17:50

Personally for me, because I use my truck for heavy duty work, the 4.10's are awesome. The 5 speed has the low gear and combined low and 4.10 gears mean this truck could climb a tree without breaking a sweat. Example of this was when I had 60 sixty to sixty-five pound bales on the back and was delivering up a mountainside. The truck hauled the whole way without having to rev it high. Once there, I had to turn around on a hill and back over the curb. Did both things without having to touch the throttle. Just let the clutch out. My previous hauling truck was an older Ford with 2.75 gearing and big block six. I had to have the engine screaming to get power out of it with a ton on the back. The 4.10's are so much better for pulling power. I've also had the truck at just over 170 kmh on a road trip, but at this point it was howling. (Not recommended again.) So for a work truck, my points go to the 4.10 gearing.

**bmp34** · 02-21-2007, 22:28

I got 93 4x4 5sp with 4.10, i found a 2-3in lift for $150 that i plan on putting 33x12.50 on a 17x8 rim which should help me with highway mileage. What do you guys think?

**DA BIG ONE** · 02-22-2007, 05:22

Originally Posted by bmp34

I got 93 4x4 5sp with 4.10, i found a 2-3in lift for $150 that i plan on putting 33x12.50 on a 17x8 rim which should help me with highway mileage. What do you guys think?

Drag will increase w/lift. I run 33"x11.5" w/o lift happy w/it...........

**moondoggie** · 02-22-2007, 08:27

Good Day!

As above, lifting increases drag. Those tires are pretty wide, which will also increase rolling resistance. Look at the high-mph vehicles - they like to put skinny hard tires on them to minimize rolling resistance.

I think it'll look cool & cost more to drive.

Good Luck & Blessings!

**bmp34** · 02-25-2007, 23:05

well i am really set on getting these 17x8 rims, and was really set on getting 33x12.50 MT MTX. I like tall skinny tires but cant find any with a all-terrain tread with a skinny tire. Could you guys help me out. Also the tires have to be somewhat cheap

**baker2acre** · 02-26-2007, 13:09

Boy, that sounds like the ideal lady... tall.... skinny... likes mud, and CHEAP!!!!

bmp34, I'm just messing around.... honestly though, specialty and economy don't usually get put on the same invoice. In the same token, I don't know that I've seen an "aggressive" tread on a low profile tire either. Low profile's are usually reserved for "high-performance street" use where the need for low tire roll from hard cornering supercede the need for shock absorbtion of off-road impacts. However, I've been wrong before, so I'll take a look-see.

**bmp34** · 02-27-2007, 00:18

Well i see yokahama makes some pretty tall skinny tires but i cant figure out the sizes, the only ones i know how to read are when they say 33x12.50 not 305/75r or whatever

**DmaxMaverick** · 02-27-2007, 01:46

Originally Posted by bmp34

Well i see yokahama makes some pretty tall skinny tires but i cant figure out the sizes, the only ones i know how to read are when they say 33x12.50 not 305/75r or whatever

The tire sizes are really pretty simple. Stop reading here if you are scared of a little math.

For example, LT305/75R/16. The LT is Light Truck, P is Passenger, and R is Radial.

The 305 is the tread width in milimeters (305mm). The 75 is the height of the sidewall, as a percentage of the tread width (75% of 305mm). The 16 is the wheel diameter, in inches.

So.....305mm = ~12", and the sidewall height is ~9" (75% of 12"). There are 2 sidewall heights (above and below the wheel), so there is a total of 18" of sidewall. Add the wheel diameter, and the tire height is ~34". Or....34x12x16. The actual numbers won't be exact, but neither are the tire manufacturers stated sizes.

I could have given you a link to a tire size calculator, but didn't (obviously). Give a man a fish, and he'll eat for a day. Teach him to fish, and he'll eat for a lifetime.

**Scooby** · 03-01-2007, 04:28

"Give a man a fish, and he'll eat for a day. Teach him to fish, and he'll eat for a lifetime."

DMAX- That is true, but it does depend on the fish. !! I have found them very uncooperative. !!!

**DmaxMaverick** · 03-01-2007, 09:09

Originally Posted by Scooby

"Give a man a fish, and he'll eat for a day. Teach him to fish, and he'll eat for a lifetime."

DMAX- That is true, but it does depend on the fish. !! I have found them very uncooperative. !!!

No problem. I'm not going anywhere. If it doesn't work out the first time, we'll still be around, and I always have lots of fish. You can live on carp, if you have to.

**jasondmann** · 04-01-2007, 18:28

Another good option for tall skinny tires are military tires. They have a very agressive tread pattern but are extreemly hard (something like 10 ply) I would only recomend if you are going for the look not performance, however they will never wear out even when used on road.

Jason

PS: This is my first post, these forums have a lot of info and it seams that I have a lot of reading to do... Anyway I am currently runing 285/75/16 through 3.73 with a 2" lift, I'll let you know how fuel economy is in a couple of weeks.

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I like the 4.10

U maybe ok, but

Fish

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