20" Wheel Question

jmh1998 · October 30, 2007

I am looking to get a 2007 Silverado soon. I have it narrowed down to four. Two have 18" wheels the other 2 have 17" wheels. All four are LT1's. When going through the specifications and options on the chevy website it says N/A for 20" wheels on LT1. My question: If I wanted to upgrade to 20" wheels someday would I be able to?

07Graystone · October 30, 2007

You can easily upgrade later. However, IMO, you need at least a 3.73 rear gear to run 20's so you can accelerate with less strain on the tranny and go up long hills without too much downshifting. My truck has a 3.42 rear gear and I am afraid I would not like the decreased performance going from 17's to 20's. Maybe someone with that set-up can tell me otherwise. You will need to get your computer reflashed to adjust the shift points and speedo if you change to 20's.

hotwheels57 · October 30, 2007

On the new body style trucks, if your truck comes with 17" oem cast aluminum or steel wheels, you can replace them with either 18" or 20" from GM (or your favorite after market source). The bolt pattern is the same. You need only worry about larger OD and the affects on the speedometer, fuel economy, braking differences, etc.

My '07 Silverado LTZ crew cab came with 17" cast aluminum wheels. I found a new take off set of LTZ wheels on EBAY for a good price, minus tire pressure sensors. I wanted GM wheels rather than after market wheels.

I had DISCOUNT TIRE dismount the 17" and mount the 20", replacing the tire pressure sensors on the new tires/wheels. I sold the 17" and recouped half of what I paid for the 20".

I did not have my computer reflashed. This site will show you the difference in aspect ratios between your oem tires/wheels and whatever you decide to replace them with. It will also show you the difference in % of speedometer error. You can reflash or adjust your driving...

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

jmh1998 · October 30, 2007

Thanks, knowing this may not make the ones with the 18" wheels as attractive. Oh yeah, all four of these are 3.73.

VMax2007 · October 30, 2007

I have the OEM 20's on my Sierra and next summer I think I am going to buy some aftermarket chrome 20's with some decent street tires. Then I will sell my OEM 20" wheels/tires and buy some OEM 17's with a nice A/T tire for use in the wintertime. I will try to keep the OD the same, if not, my Edge programmer has tire size settings to recalibrate my ECM.

Anyone interested in OEM 20" GMC wheels with GoodYear tires next spring? I actually have 5 wheels, but only 4 with tires...long story, don't ask.

jmh1998 · October 30, 2007

I have the OEM 20's on my Sierra and next summer I think I am going to buy some aftermarket chrome 20's with some decent street tires. Then I will sell my OEM 20" wheels/tires and buy some OEM 17's with a nice A/T tire for use in the wintertime. I will try to keep the OD the same, if not, my Edge programmer has tire size settings to recalibrate my ECM.

Anyone interested in OEM 20" GMC wheels with GoodYear tires next spring? I actually have 5 wheels, but only 4 with tires...long story, don't ask.

That is what I figure I would do, keep the 17 (or 18) and put snow tires on them for the winter. Next spring would probably be too early for me to get your wheels, unless I hit the lottery.

07SLT · October 30, 2007

Are the stock 20" Goodyear tires that bad in the snow? I hope not! I just bought my 07 Sierra with 20's in August and live in Minnesota.

VMax2007 · October 30, 2007

Are the stock 20" Goodyear tires that bad in the snow? I hope not! I just bought my 07 Sierra with 20's in August and live in Minnesota.

I also live in MN and I bought got mine in March, right after that last snowstorm. Haven't had a chance to really find out, but my expectations are pretty low since they are not very aggressive, are low profile and a street tire. Plus I am not a huge fan of Goodyears anyway. My old 2000 had 285/75/16 BF Goodrich All Terrain T/A's on it and they were awesome.

Where in MN are you?

cerbomark · October 30, 2007

I replaced my 18 with 20 from the dealer. No issues except maybe less MPG s and harder ride. I m happy with them and live in the NY snowbelt and have never had issues with the Goodyears.

MaxLTZ · October 30, 2007

I am looking to get a 2007 Silverado soon. I have it narrowed down to four. Two have 18" wheels the other 2 have 17" wheels. All four are LT1's. When going through the specifications and options on the chevy website it says N/A for 20" wheels on LT1. My question: If I wanted to upgrade to 20" wheels someday would I be able to?

Hello Joe:

Just so has it that I just took my 20" '07 wheels and tires off and am looking to sell. They only have around 600 miles on them. Let me know if you're interested.

Thanks

jmh1998 · October 30, 2007

I am looking to get a 2007 Silverado soon. I have it narrowed down to four. Two have 18" wheels the other 2 have 17" wheels. All four are LT1's. When going through the specifications and options on the chevy website it says N/A for 20" wheels on LT1. My question: If I wanted to upgrade to 20" wheels someday would I be able to?

Hello Joe:

Just so has it that I just took my 20" '07 wheels and tires off and am looking to sell. They only have around 600 miles on them. Let me know if you're interested.

Thanks

i wish I could, they look nice. But that purchase would have to be a bit down the road. I don't even have the truck yet. I am trying to hold out as long as I can to get the best incentives and to increase my trade in value.

skp05 · October 30, 2007

I am looking to get a 2007 Silverado soon. I have it narrowed down to four. Two have 18" wheels the other 2 have 17" wheels. All four are LT1's. When going through the specifications and options on the chevy website it says N/A for 20" wheels on LT1. My question: If I wanted to upgrade to 20" wheels someday would I be able to?

The 17" wheels/tires. (265/70/r17) vs. the 20" stock size (275/55/r20) is very close is the R.P.M. specs. Per mile there is only 8 revolutions difference (660(17") vs. 652(20") I wanted the 20" wheels when I ordered mine but they will not let you have 20" wheels with the VMAX(NHT) package, which is funny because all the original pics from Chevrolet showed the GMT900 VMAX with 20's.

I purchased 20" tahoe wheels and tires off ebay and they work great and the speedo is dead on with a G.P.S. and backs up the spec on the tires diameter. Sold my original tires and the upgrade didn't cost me anymore than if I ordered them new on the truck. They even came with the sensors installed.

The only reason I could see why they don't allow 20"s on the VMAX is the weight difference on the tires is 100 lbs. per tire or a total of 400 which reduces the towing/payload capability.

VMax2007 · October 30, 2007

I am looking to get a 2007 Silverado soon. I have it narrowed down to four. Two have 18" wheels the other 2 have 17" wheels. All four are LT1's. When going through the specifications and options on the chevy website it says N/A for 20" wheels on LT1. My question: If I wanted to upgrade to 20" wheels someday would I be able to?

The 17" wheels/tires. (265/70/r17) vs. the 20" stock size (275/55/r20) is very close is the R.P.M. specs. Per mile there is only 8 revolutions difference (660(17") vs. 652(20") I wanted the 20" wheels when I ordered mine but they will not let you have 20" wheels with the VMAX(NHT) package, which is funny because all the original pics from Chevrolet showed the GMT900 VMAX with 20's.

I purchased 20" tahoe wheels and tires off ebay and they work great and the speedo is dead on with a G.P.S. and backs up the spec on the tires diameter. Sold my original tires and the upgrade didn't cost me anymore than if I ordered them new on the truck. They even came with the sensors installed.

The only reason I could see why they don't allow 20"s on the VMAX is the weight difference on the tires is 100 lbs. per tire or a total of 400 which reduces the towing/payload capability.

Clarification: The 20's are not available on the NHT (max trailering pkg) but they are available on the Vmax (see my sig pic). It has to do with the Z60 suspension that the 20" wheels require, this is a street suspension and lowers the towing capability somewhat. Also, the non-NHT Vmax has 3.73 gears, which also lowers the towing cap. In hindsight, I wish I had ordered the NHT pkg and gotten the 17" wheels. then I could have just bought some chrome aftermarket 20's for the summer and used the OEM 17's in the winter. Oh well, I figure if I buy some chrome 20's next spring, I should be able to sell my OEM 20's for the same amount I pay for some OEM 17's for winter use. Same difference I guess. Maybe I'll just keep the OEM 20's and put some better winter tires on them, if I can find them for a decent price.

topdj · October 30, 2007

I have both the GM factory 17"s and the factory 20"s with the extra bling of "custom chrome plate" the measured circumfrence "not calculated!!" is 99.25 inches for the 17" Goodyears and 101.125 inches for the 20" BFG's. 63360 inches in`a mile 638 revs per mile for the 17"s 626 revs per mile for the 20"s I did not feel any real difference between the tires except for ride & handling.

07SLT · October 30, 2007

Are the stock 20" Goodyear tires that bad in the snow? I hope not! I just bought my 07 Sierra with 20's in August and live in Minnesota.

I also live in MN and I bought got mine in March, right after that last snowstorm. Haven't had a chance to really find out, but my expectations are pretty low since they are not very aggressive, are low profile and a street tire. Plus I am not a huge fan of Goodyears anyway. My old 2000 had 285/75/16 BF Goodrich All Terrain T/A's on it and they were awesome.

Where in MN are you?

Thanks for the info.....I'm in the Rochester area.