Gm Says 20in Wheels And Off-road A No-no!

[leverlution]

Doesn't much matter to me, I got the 17s. 20s look nice I guess, but I didn't want the extra cost for tires and everything else. Just thought I would give you guys a heads up though, I saw this in the manual while checking something else. 2010 Silverado owners manual clearly states 20in wheel vehicles, even with four wheel drive should NOT be driven on anything other than flat/solid roads. I guess hard packed dirt roads are covered in this.

 

Not a big deal, just wanted to put this out there for those researching a new truck and may have to get it a little dirty if they own property or something. May want to keep that in mind. For those of you with factory 20in wheels that have to get it a little dirty once in awhile, or even if you put aftermarket 20in wheels on it, make sure you clean it up before a trip to the dealer, or at least keep it in your head to tell them it was on a solid road with some puddles. Just a heads up Here is the copy from a PDF manual for reference:

 

Off-Road Driving

 

Vehicles with four-wheel drive can be used for off-road

 

driving. Vehicles without four-wheel drive and vehicles

 

with 20?inch tire/wheel assemblies should not be driven

 

off-road except on a level, solid surface.

 

I would think in the "warranty world," short of a good dealer, or a not too large cost repair, "Should not" is basically "not covered." Probably wouldn't have any problems, but if the dealer wants to be a pain, or the cost of a transmission/rear end is making an accountants eyeballs roll a little bit, you might have some problems.

 

On the plus side, you guys might want to keep your manual, or a PDF copy for the "Vehicles with four-wheel drive CAN BE USED FOR OFF-ROAD DRIVING part." :-)

[zcs626]

i'm sure it isn't as bad as they make it seem to be. they're covering their asses.

[Daryl LBZ]

The 20 Inch wheels still leave a good bit of sidewall on the tires don't they?

[heelshock]

Doesn't much matter to me, I got the 17s. 20s look nice I guess, but I didn't want the extra cost for tires and everything else. Just thought I would give you guys a heads up though, I saw this in the manual while checking something else. 2010 Silverado owners manual clearly states 20in wheel vehicles, even with four wheel drive should NOT be driven on anything other than flat/solid roads. I guess hard packed dirt roads are covered in this.

 

Not a big deal, just wanted to put this out there for those researching a new truck and may have to get it a little dirty if they own property or something. May want to keep that in mind. For those of you with factory 20in wheels that have to get it a little dirty once in awhile, or even if you put aftermarket 20in wheels on it, make sure you clean it up before a trip to the dealer, or at least keep it in your head to tell them it was on a solid road with some puddles. Just a heads up Here is the copy from a PDF manual for reference:

 

Off-Road Driving

 

Vehicles with four-wheel drive can be used for off-road

 

driving. Vehicles without four-wheel drive and vehicles

 

with 20?inch tire/wheel assemblies should not be driven

 

off-road except on a level, solid surface.

 

I would think in the "warranty world," short of a good dealer, or a not too large cost repair, "Should not" is basically "not covered." Probably wouldn't have any problems, but if the dealer wants to be a pain, or the cost of a transmission/rear end is making an accountants eyeballs roll a little bit, you might have some problems.

 

On the plus side, you guys might want to keep your manual, or a PDF copy for the "Vehicles with four-wheel drive CAN BE USED FOR OFF-ROAD DRIVING part." :-)

 

I'm a former Jeep rock crawler. I can say from experience that a 20" rim has no business being used offroad. In fact, I never used anything over a 16", and that was with 37's. Minimum sidewall tires can't be aired down which is a necessity for true offroad applications. The sidewall needs to flex, and as you street runners know, those low profile tires are hard as a rock.

 

BC

[leverlution]

i'm sure it isn't as bad as they make it seem to be. they're covering their asses.

 

Oh, I agree, but because they C.T.A, people may have warranty problems. I was just letting everyone know it IS is in the manual, especially for those shopping. If you got 20s and need to get it dirty, make sure you clean it up a little before taking it, and tell them it was a hard packed dirt road with some puddles.

[leverlution]

The 20 Inch wheels still leave a good bit of sidewall on the tires don't they?

 

IMO, not really. They aren't too too bad like on a Honda, but they still don't leave a lot of cushion for sharp impacts. Plus, as said above me, they can't really be aired down for crap. Also, because of the decreased "cushion," the wheels and also suspension parts, can take bigger hits.

[crepitus]

Honestly who is going to take their $30K plus truck off road that bad they are going to need anything more then 20s with AT? If they do they have money to burn and then would not care about warranty.

[leverlution]

Honestly who is going to take their $30K plus truck off road that bad they are going to need anything more then 20s with AT? If they do they have money to burn and then would not care about warranty.

 

You would be suprised!! LoL! My old Wrangler Rubicon was 30+ new, and I knew a lot of people with that same truck, 15k+ aftermarket parts, and used them as trailered off road only Jeeps!! I have a few properties totaling over 450acres in WV, one of which is over 300. I used my chevy to check the property, get wood, check the oil/gas trails for fallen trees/vandalism etc. Now, like you said, I don't take my new truck up in the hills(basically heavy mountain wheeling) like my Jeep, but one day it will have to when its older/payed off.

 

I was more mentioning it for construction supervisors, loggers, people with farm properties etc that are looking to buy. If youj *have* to have an LTZ, make sure you have the 20s swapped for 17s at the dealer, or order the Z71 with the 18s.

[Stex]

It is not the wheel so much as the lack of sidewall. I think GM means serious off road (rock crawls etc) and would be ok for hunting lease, pasture etc...The 20 inch will flex more and rock crawls may damage do to lack of sidewall...you can go off road with the 20s just not hard core off road...

 

The reason they do not put 20s on z-71 is more to do with the harsh ride. I have 18s but when testing trucks the 17s on the z-71 rode better...20s would be too harsh...

[pm26]

I'm a former Jeep rock crawler. I can say from experience that a 20" rim has no business being used offroad. In fact, I never used anything over a 16", and that was with 37's. Minimum sidewall tires can't be aired down which is a necessity for true offroad applications. The sidewall needs to flex, and as you street runners know, those low profile tires are hard as a rock.

 

BC

 

Except of course, on large vehicles. My deuce and half has 20 inch wheels, but the tires have 10 inch sidewall height, so each tire is 40" tall when properly inflated.

[maxco]

I just went up north a couple weeks ago, and my buddy drove his Sierra with 20" wheels, and there was a couple spots where you had to crawl over rocks, nothing too serious, but the tires do still flex. He had no problems with it, mind you we went slow and didn't drive stupidly over the rougher sections. I would much rather have my 18s to drive in that kind of situation but I think if you are smart about it, it's not a big deal. You just can't expect the sidewall on the 20 to flex as much as the 18 so a little more caution needs to be given.

[leverlution]

I agree with you guys that's its possible for mild/normal outdoor situations. Maybe not ideal, but there is nothing wrong with it for hunting or driving around your property etc.

 

My point, as I said before, wasn't whether or not it was a good idea, or even possible(although the inputs have been informative), it was merely that the GM owners manual states 20in wheels are NOT to be used offroad except for solid surfaces. Because the owners manual says it, you *MAY* have a warranty situation in a worst case scenario. Again, it was simply a heads up to clean your vehicle before taking it in with 20in wheels, and if you are researching a new Chevy GMC, just keep in mind that 20in wheel vehicles *may* have warranty issues if used in an offroad situation, and your dealer/regional dude/GM feels like being company orriented and not customer orriented.

 

That's all I was trying to say. Just to have something that pops up on google search for anyone researching a gmt900 silverado/sierra.

[obxdiver]

I have taken my Sierra Denali with OEM 20's in the sand with no problems.

I did not air down either. Stayed at 30psi

[Daryl LBZ]

Honestly who is going to take their $30K plus truck off road that bad they are going to need anything more then 20s with AT? If they do they have money to burn and then would not care about warranty.

 

 

 

Lol yea really. I like my nice 18" wheels.

[gnet158]

Not entirely true. I read that in the owners manual too, but there's something else in there that clearly states it's ok. I'll have to look for it tonight when I get home.

 

Otherwise, why would they sell trucks with factory 20' wheels? I've been in the canyon's (in the sig background) and haven't had any problems. That said I've never and would never rock crawl or anything like that.