20 inch rims on PPV tahoe

[ppvtahoe247]

about time for some tires on the PPV but i can get a good deal on some 20s already mounted and balanced. I know they're taller than the 17s so it'll throw off the speedo but other than that, how has this affected the driveability? I've heard rumors that it slows these down a bit perhaps because of the rear end ratio or whatever but I can't imagine it would be that drastic.

Who's done this and how did it affect the ride and performance of your PPV?

 

[CrashTestDummy]

The larger diameter will definitely drop the effective gear ratio, which will affect acceleration. Add to that the increased unsprung weight. It takes a LOT more energy to start those big tires rotating. I'll bet you feel it.

OTOH, you'll gain some top end, albeit the speedo will say the same, but Officer Fife will be issuing you a ticket for more than what the speedo read!

 

[ppvtahoe247]

Thanks! I know there will be a little compromise here. It'll raise it up and it'll slow it down but to what degree i don't know.

You would think it's a common swap...how bad or good is it?

What's the final drive ratio on a PPV?

 

[tgwhit12]

about time for some tires on the PPV but i can get a good deal on some 20s already mounted and balanced. I know they're taller than the 17s so it'll throw off the speedo but other than that, how has this affected the driveability? I've heard rumors that it slows these down a bit perhaps because of the rear end ratio or whatever but I can't imagine it would be that drastic.

Who's done this and how did it affect the ride and performance of your PPV?

I have two PPVs. An 11 and a 13. 20's are great. I put 20s on both. Both PPVs came with 3:08 rear axles. One was open and the other was an interlocker. When you put 20s in GM factory size 275-55-20 you lower the ration to 2:80 or so. I can't remember exactly. It's actually ok on take off because of the 6 speed. The big difference for me was on a longer trip. It sucked there. I drive about 10mph over. If you're running with your curise on 78 -80, the truck downshifts way too much to please me. IIRC, with 20s and the 3:08 rear end, your RPM is around 1700. It's too low to pull any slight grade with out downshifting. I switched my 13 to the factory 3:43 and drove the truck from Memphis to the other side of Denver. A gradual uphill. The truck rarely downshifted, turned about 2,000 -2,100 RPM and got about 20MPG.
For me, the 3:43 to 3:73 is best with the 6 speed and 20s.
I disliked the weakness in high gear so much on the 11, I went back to 17 inch wheels on the 11 tahoe. It's better, but I'm still always looking for a low mileage rear end for the 11. I still don't like the performance. That's just me.

 

[blackelky]

How much did the 3.42s run thinking about doing the same thing myself

 

[blackelky]

I have two PPVs. An 11 and a 13. 20's are great. I put 20s on both. Both PPVs came with 3:08 rear axles. One was open and the other was an interlocker. When you put 20s in GM factory size 275-55-20 you lower the ration to 2:80 or so. I can't remember exactly. It's actually ok on take off because of the 6 speed. The big difference for me was on a longer trip. It sucked there. I drive about 10mph over. If you're running with your curise on 78 -80, the truck downshifts way too much to please me. IIRC, with 20s and the 3:08 rear end, your RPM is around 1700. It's too low to pull any slight grade with out downshifting. I switched my 13 to the factory 3:43 and drove the truck from Memphis to the other side of Denver. A gradual uphill. The truck rarely downshifted, turned about 2,000 -2,100 RPM and got about 20MPG.
For me, the 3:43 to 3:73 is best with the 6 speed and 20s.
I disliked the weakness in high gear so much on the 11, I went back to 17 inch wheels on the 11 tahoe. It's better, but I'm still always looking for a low mileage rear end for the 11. I still don't like the performance. That's just me.

How much did the 3.42s run thinking about doing the same thing myself

 

[tgwhit12]

I looked on FB for a while. There were plenty in the $500 - $600 range. I found a guy in AR at a small yard who had just taken in an 80K mile Yukon with at 3.42 interlocker. I pulled reports to be sure. A lady had owned it. The guy pulled it for me $325.00. I put it in. I changed the fluid, but wished that I hadn't; it was pristine.