285 From 265 ?'s

[ace ventura]

I'm looking to go to 285's from 265's. I have a few questions.

 

1. Will it rub at full lock?

2. What can I expect in loss to gas mileage?

3. Will my ride change from the Bridgestone's to BFG A/T?

4. Will a tune bring the mileage back up as well as power?

5. I have the 3.42 gears is this a mistake because I tow a popup which weighs 2800 pounds?

 

Thanks for the help!

[K.Jump]

I'm looking to go to 285's from 265's. I have a few questions.

 

1. Will it rub at full lock?

2. What can I expect in loss to gas mileage?

3. Will my ride change from the Bridgestone's to BFG A/T?

4. Will a tune bring the mileage back up as well as power?

5. I have the 3.42 gears is this a mistake because I tow a popup which weighs 2800 pounds?

 

Thanks for the help!

 

1. no

2. not much, maybe 1mpg

3. ride should get better( more rubber cushions the ride)

4. it definately will help

5. 3.42= ah it will be alright

6. GET R DONE

[ace ventura]

Your truck looks awesome!! thanks for the reply.

 

Other opinions welcome.

[svensk]

If you have 3.42 gears forget it. That would lower your ratio even further to something like 2.91 assuming the stock tire is 245. Don't get me wrong the ride quality will be better, but not good enough in my opinion to justify how big of a slug your truck will be out of the hole.

[automan01]

I'm looking to go to 285's from 265's. I have a few questions.

 

1. Will it rub at full lock?

2. What can I expect in loss to gas mileage?

3. Will my ride change from the Bridgestone's to BFG A/T?

4. Will a tune bring the mileage back up as well as power?

5. I have the 3.42 gears is this a mistake because I tow a popup which weighs 2800 pounds?

 

Thanks for the help!

 

 

1. Not if you crank you torsion bars up.

2. 1-3mpg's

3. Depends on tire

4. No

5. don't know

I have a 2004 Silverado, I put 285/70R17 Firestone Destination M/Ts on my truck. Love the tires and looks but did come at a cost. I lost fuel ecnomy big time, had to crank to torsion bars up almost all the way, which now it rides way stiffer. I also used a tuner which did not bring my mpg's up at all.

[K.Jump]

I'm looking to go to 285's from 265's. I have a few questions.

 

1. Will it rub at full lock?

2. What can I expect in loss to gas mileage?

3. Will my ride change from the Bridgestone's to BFG A/T?

4. Will a tune bring the mileage back up as well as power?

5. I have the 3.42 gears is this a mistake because I tow a popup which weighs 2800 pounds?

 

Thanks for the help!

 

 

1. Not if you crank you torsion bars up.

2. 1-3mpg's

3. Depends on tire

4. No

5. don't know

I have a 2004 Silverado, I put 285/70R17 Firestone Destination M/Ts on my truck. Love the tires and looks but did come at a cost. I lost fuel ecnomy big time, had to crank to torsion bars up almost all the way, which now it rides way stiffer. I also used a tuner which did not bring my mpg's up at all.

 

 

 

I'v had 285s on both my 99 RCSB and my 00 ECSB with no TB crank and no rub what-so-ever!

 

 

 

 

 

 

 

[2004GMC1500CC]

Your truck looks awesome!! thanks for the reply.

 

Other opinions welcome.

It's not necessarily the width (285) its the height. If you get a shorter tire it will fit fine. Here is mine with a 285/60/18 and it is a stock 2wd.

[Zembonez]

285 BFGs with 3.42s will be OK just driving around. You won't notice much difference from the 265s. Ride will be a little rougher with the BFGs but I think you'll like it. They are awesome tires. Mileage might suffer a little. I lost a good mile per gallon when I went to bigger tires. Towing much weight might become an issue with the taller tires. I would add a trans cooler if you don't already have.

[Bostonsfavson]

If you have 3.42 gears forget it. That would lower your ratio even further to something like 2.91 assuming the stock tire is 245. Don't get me wrong the ride quality will be better, but not good enough in my opinion to justify how big of a slug your truck will be out of the hole.

 

 

I thought it was only the overall height of the tire that affected drive ratio, not the width. Am I incorrect?

[2000DV4.8]

If you have 3.42 gears forget it. That would lower your ratio even further to something like 2.91 assuming the stock tire is 245. Don't get me wrong the ride quality will be better, but not good enough in my opinion to justify how big of a slug your truck will be out of the hole.

 

 

I thought it was only the overall height of the tire that affected drive ratio, not the width. Am I incorrect?

 

 

 

You are correct, but the 285's will likely be a larger diameter tire than the 265's, as they usually have the same aspect ratio.

[pm26]

If you have 3.42 gears forget it. That would lower your ratio even further to something like 2.91 assuming the stock tire is 245. Don't get me wrong the ride quality will be better, but not good enough in my opinion to justify how big of a slug your truck will be out of the hole.

 

 

I thought it was only the overall height of the tire that affected drive ratio, not the width. Am I incorrect?

 

 

Yes, it is only the height of the tire that will affect the final drive ratio, but wider tires like 285's with the same aspect ratio are taller than 265's with the same aspect ratio. The reason is simple:

 

285 X0.70 is more than 265 X 0.70. those numbers will give you the height of the sidewall. Take the difference, multiply by 2, divide by 25.4 to convert milimeters to inches and you will see how much taller a 285/70 tire will be.

 

Height of a 265/70R17 tire: [ 2 X 265X 0.70]/25.4 + 17 = 31.6 inches

 

Height of a 285/70R17 tire: [2 X 285 X 070]/25.4 + 17 = 32.7 inches

 

The difference in diameter is 3.4 % . The reduction in gearing is directly proportional to the diameter difference, so the new effective gear ratio, given the original 3.42 gears, is 3.30. So slightly taller gears, but not terrible.

[VMax2007]

Here is a link to handy tire size calculator.

 

http://www.miata.net/garage/tirecalc.html

[Tylerz71]

DO IT!

I just got my 285/70-17 Kumho Road Venture AT's put on my 2000 Sierra. All i did was crank the torsion bars just a little.

Yes, it rides a little bit rougher, BUT when you see how it looks, I promise you will say its was worth it.

My power is still there, didnt notice much of a loss. But im running 3:73's. With 3:42's you will notice a good hit out of power if you tow.

 

Mine scrub a little, ONLY when turning left while backing up. And Ill let the tires fix that.

Ill have pictures up shortly.

[pm26]

DO IT!

I just got my 285/70-17 Kumho Road Venture AT's put on my 2000 Sierra. All i did was crank the torsion bars just a little.

Yes, it rides a little bit rougher, BUT when you see how it looks, I promise you will say its was worth it.

My power is still there, didnt notice much of a loss. But im running 3:73's. With 3:42's you will notice a good hit out of power if you tow.

 

Mine scrub a little, ONLY when turning left while backing up. And Ill let the tires fix that.

Ill have pictures up shortly.

 

Your new effective gearing is 3.60s, down from the original 3.73. 3.4% less torque at the rear wheels.

[Tylerz71]

Hmm... thanks for that fact!

 

and my speedometer is 3.349% slow.