20" Stock Wheels vs 18" Stock Wheels

[hawk99gt]

Why does Chevy for the same TB's out there put 20" wheels & 18"? Is one better than the other? My LT TB came with 18's. I wasn't sure if that was good thing or bad thing. I was used to driving with 20" wheels on my RAM, but noticed a lot of off-roaders were using smaller rims with huge tires mounted to them. Just trying to figure what are the advantages or pros & cons of each.
When I was at my dealership the other day getting some work done, I saw that they sell Fuel Wheels. I think they were like 23". I asked about them and the service guy was telling me that yeah we can add them on to yours. But I am thinking to myself, yeah but I am going to need tires to match and a lift to accommodate that setup. Plus I told him that I would have to get my speedo adjusted and a larger spare (17").
He was like, no you can use your existing spare and as far as the speedo adjustment it would be very minimal that I wouldn't need to have the adjustment done.
I think he is smoking something and trying to blow it up my kilt.
Let me know your thoughts.

 

[GETGONE]

You'll rarely see any wheel size in an odd number above 19". I'm not aware of any 23" wheels. They were 22" or 24". Overall tire diameter is what matters, NOT wheels size. You put a smaller aspect ratio tire(shorter sidewall) to accomplish this. 20's are a visual thing. Hardcore offroaders want smaller rims and larger sidewalls so they can air down to crawl over rocks and other obstacles. I opted for the 20's when I ordered my truck since it was only a $500 option. For me it also bumps up the speed limiter to 112mph vs 98mph for the 18's due to the 20's having a higher speed rating.

 

[hawk99gt]

You'll rarely see any wheel size in an odd number above 19". I'm not aware of any 23" wheels. They were 22" or 24". Overall tire diameter is what matters, NOT wheels size. You put a smaller aspect ratio tire(shorter sidewall) to accomplish this. 20's are a visual thing. Hardcore offroaders want smaller rims and larger sidewalls so they can air down to crawl over rocks and other obstacles. I opted for the 20's when I ordered my truck since it was only a $500 option. For me it also bumps up the speed limiter to 112mph vs 98mph for the 18's due to the 20's having a higher speed rating.

Thanks, GETGONE! for the info and enlightenment. The 23'' could be my bad listening to the service guy. I thought thats what he said. Not sure I would take advice from that particular service guy, anyway.
So if I understand you, the wheel diameter of the (stock) 20's and the 18's are the same. The 20's just have a lower profile.

 

[Stormin08]

typically, the OE overall dia will be very close...
again, the larger side wall (small rim) will offer a softer ride, the shorter side wall (larger rim) will offer better higher speed handling

good rule is this, a tire 2x the diameter of the wheel offers the best ride and handling combined...go either direction and one of those will suffer

i recently read someone mention the SOFT suspension of the TB for offroading flex capabilities...i cannot tell you how HARSH i think the ride is (that is mostly the ranchos)...but the addition of a 22" wheel did not help that cause. my rear end jumps side to side all day long. I plant to start with a light valved shock, but may ultimately drop back to a 20 (stock on my truck) or even an 18 to soften the ride.

but for now, the look is what i was after

 

[YellowStones]

Why does Chevy for the same TB's out there put 20" wheels & 18"? Is one better than the other? My LT TB came with 18's. I wasn't sure if that was good thing or bad thing. I was used to driving with 20" wheels on my RAM, but noticed a lot of off-roaders were using smaller rims with huge tires mounted to them. Just trying to figure what are the advantages or pros & cons of each.
When I was at my dealership the other day getting some work done, I saw that they sell Fuel Wheels. I think they were like 23". I asked about them and the service guy was telling me that yeah we can add them on to yours. But I am thinking to myself, yeah but I am going to need tires to match and a lift to accommodate that setup. Plus I told him that I would have to get my speedo adjusted and a larger spare (17").
He was like, no you can use your existing spare and as far as the speedo adjustment it would be very minimal that I wouldn't need to have the adjustment done.
I think he is smoking something and trying to blow it up my kilt.
Let me know your thoughts.

Does your wife like the speedo????

 

[hawk99gt]

Does your wife like the speedo????

Why yes she does....

 

[Gangly]

Why does Chevy for the same TB's out there put 20" wheels & 18"? Is one better than the other? My LT TB came with 18's. I wasn't sure if that was good thing or bad thing. I was used to driving with 20" wheels on my RAM, but noticed a lot of off-roaders were using smaller rims with huge tires mounted to them. Just trying to figure what are the advantages or pros & cons of each.
When I was at my dealership the other day getting some work done, I saw that they sell Fuel Wheels. I think they were like 23". I asked about them and the service guy was telling me that yeah we can add them on to yours. But I am thinking to myself, yeah but I am going to need tires to match and a lift to accommodate that setup. Plus I told him that I would have to get my speedo adjusted and a larger spare (17").
He was like, no you can use your existing spare and as far as the speedo adjustment it would be very minimal that I wouldn't need to have the adjustment done.
I think he is smoking something and trying to blow it up my kilt.
Let me know your thoughts.

On TIRES with equivalent diameter, a smaller WHEEL(18" v 20") will have more sidewall which is preferable for off road enthusiasts. Basically an 18" wheel with 35" tires has more sidewall than a 20" wheel with 35" tires. Extra sidewall gives you additional ability to lower tire pressures and increase your contact patch when off road.

 

[fotoguy21159]

typically, the OE overall dia will be very close...
again, the larger side wall (small rim) will offer a softer ride, the shorter side wall (larger rim) will offer better higher speed handling

good rule is this, a tire 2x the diameter of the wheel offers the best ride and handling combined...go either direction and one of those will suffer

i recently read someone mention the SOFT suspension of the TB for offroading flex capabilities...i cannot tell you how HARSH i think the ride is (that is mostly the ranchos)...but the addition of a 22" wheel did not help that cause. my rear end jumps side to side all day long. I plant to start with a light valved shock, but may ultimately drop back to a 20 (stock on my truck) or even an 18 to soften the ride.

but for now, the look is what i was after

I agree about the harsh ride, that's probably why the 22" wheels aren't an option with the Z71 as it would make it even worse.

 

[GETGONE]

Does your wife like the speedo????

A guy I used to work with called it a speedoww

 

[SBE 2]

Why does Chevy for the same TB's out there put 20" wheels & 18"? Is one better than the other? My LT TB came with 18's. I wasn't sure if that was good thing or bad thing. I was used to driving with 20" wheels on my RAM, but noticed a lot of off-roaders were using smaller rims with huge tires mounted to them. Just trying to figure what are the advantages or pros & cons of each.
When I was at my dealership the other day getting some work done, I saw that they sell Fuel Wheels. I think they were like 23". I asked about them and the service guy was telling me that yeah we can add them on to yours. But I am thinking to myself, yeah but I am going to need tires to match and a lift to accommodate that setup. Plus I told him that I would have to get my speedo adjusted and a larger spare (17").
He was like, no you can use your existing spare and as far as the speedo adjustment it would be very minimal that I wouldn't need to have the adjustment done.
I think he is smoking something and trying to blow it up my kilt.
Let me know your thoughts.

hawk. All of the serious off-roaders out there prefer the '18's. I have to agree with them. I run the stock 20's. One thing for sure is that there is to much over steer for any serious off road stuff. This is my option only.

 

[Gangly]

In addition to what I added earlier, the additional sidewall you have with 18's can really make a difference in comfort when you air down for trail riding, or wash board dirt roads. The taller sidewall acts like a dampener on harsh roads and can really smoothen out rough trails.

 

[Peisel]

Thanks, GETGONE! for the info and enlightenment. The 23'' could be my bad listening to the service guy. I thought thats what he said. Not sure I would take advice from that particular service guy, anyway.
So if I understand you, the wheel diameter of the (stock) 20's and the 18's are the same. The 20's just have a lower profile.

my reason for wanting smaller rims so that i dont scuff them when parking... I like having the side walls larger and thicker so sharp rocks dont puncture. plus lower psi when playing in ice and mud. I have the 20" rims and i want to smack the engineer who thought to put 20's on a trail truck... haha he must live in the city... one who buys a 4x4 which never spends a day on dirt and never shifted to 4wd... just my opinion, if it offends disregard.

Ive been researching on how small a rim can go on the TB? What size would interfere with brake calibers?

edit:
Tool for comparing tire and rim sizes:

Tire Size Comparison

Tire size comparison the easy way. Use our tire size comparison calculator to compare diameter, width, sidewall, circumference and revolutions per mile.

tiresize.com

Another ?:
What are the factory 20" rim offsets? They look positive offsets but dont know by how much?

KO2's 20" has only 3 ply walls? Do smaller rim size ko2s have thicker sidewalls? My old tries (maybe kos) had 7 ply.

I have three GM products:
'21 Chevy 1500 TB 20" rims 6 lug
'62 GMC 1500 WH rims: 16" fronts 16.5" rears 8 lugs (have 16" rears too)
'57 Chevy 1500 Stepside 15" rims 5 lugs
i am hoping all my tires would be interchangeable in the near future haha

 

[GETGONE]

17's are the smallest diameter you can go and still clear the brake calipers. It also depends on the wheel style if they will clear the rib on the caliper. I believe the stock wheels are around +24mm.

 

[Peisel]

17's are the smallest diameter you can go and still clear the brake calipers. It also depends on the wheel style if they will clear the rib on the caliper. I believe the stock wheels are around +24mm.

thanks for the info

 

[PHXPHOTOG]

Most of the info above is spot on. I just want to reiterate the importance of understanding tires are your first and possibly one of the most important parts of your suspention system. It is your truck meeting the road and it matters. Looks for wheels and tires is not even on my radar. I off road a lot so my stock 18s are my priority. I need sidewall performance. It is all about what you do with your truck. That's a personal preference thing.

Steve