smooth sierra

I think this is the best advice so far I have the 275/55/20 and they are too tall. I will wear them out and then go to the 275/45/20 which is just a hair shorter than the factory tire. as far as dramatic changes in driving........when I put on the 20's I did notice a little change immediately but after driving the truck for a while I swear it is just as quick. at first it wouldn't spin the tires from a grunt. now it will light them up good. I don't know if the computer relearned and compensated for the extra height or what???

your biggest factor is the tire diameter. I vote for loosing the 275/55 in place of the 275/45. their is a picture of my truck in the sig with the 275/55 and a 2" rear drop. the 275/55 definitely fill the fenders but a little overkill for my taste. It kinda has that hotwheels look

the 265/50/20 is another option that I think is the exact height of the factory tire. either way keep the 20's, they look much better. I had no idea the SS wheels were that heavy. I would hope my forged centerlines are lighter than that

F8L Z71

My stock aluminum chevy and GMC wheels with a 275/75/16 tire weigh only 54lbs each. That's a HUGE diff. compared to those heavy 20s.

hirdlej

iTrader: (31)

So basically what you're getting at then is you think the overall tire height is going to kill me more than just the added weight of the wheel? I've read so much about sprung and unsprung weight in the last 10 hours it's not even right I think I'll try them as is, unless someone wants to buy these new tires from me with less then 100 miles on them. Then I can get some proxies or something a little more performance oriented than the goodyear LS's. By the way smooth sierra, I like your truck and the way it looks in the sig

dust6928

iTrader: (2)

with those ss wheels you will feel a difference especially with that big tire cause it is going to kill your gearing. like they said, you need to go to a 275/45 or a 265/50-20 to get closer to the factory tire height. if you got a good deal then you may consider selling them and buying a set of wheels and tires that are lighter. my stock steelies and tires weighed in at 60lbs a piece. my 20's with the 265/50's weigh in at a wopping 68lbs each. i could tell a little difference but not enough to make a difference considering the cornering gains. but i think the theory of unsprung weight (ie. heavier wheels) is for every 100lbs of unsprung weight is worth a tenth in the 1/4. so you can gauge the difference in performance by the difference in wheel weight. i would sell them though and do some research on wheels and find some lighter weight 20's like the centerline billets or something. they are inexpensive, pretty decent styling, and light. just my .02's.

smooth sierra

thanks for the compliment. I would try selling the goodyears on ebay. they are factory size for the dodge guys with 20's so maybe post them on a dodge board also. discount sells those goodyears for over 170 a piece so you should have no problem getting maybe 125 a tire and that would make a nice down payment on some better tires. the goodyears suck in the rain when compared to toyos or nittos. I personally like the nittos better but anything beats the goodyears.

you will not notice daylight and dark differences in performance. Like it was said maybe one tenth in the quarter.

F8L Z71

Compared to a light weight wheel like a Centerline you will lose up to about 3 10ths in the 1/4 I bet.

The height hurts but I htink the weight hurts more. Now if your original rims/tires weigh 70lbs then the diff. in weight isn't so bad. About a 10th maybe.

hirdlej

iTrader: (31)

Time to drag out the bathroom scale. I've got heavy michelin LTX M/S tires on facotry 16" chrome steel wheels. I only think the SS rims/tires are about 10 pounds heavier a piece. I need to put them on the scale to be certain though. I might be able to get at my truck (it's in the back garage sleeping for winter) and take one of the stock rims off with the michelins to compare weight.

Y2KSierra

iTrader: (4)

Get some smaller tires for the wheels. 275/55/20 is rediculous anyway. My stock steel wheels weighed around 59-60 on my bathroom scale and my 20" centerlines on 245/40/20 hankooks weighed 51 lbs. I'll take 9 lbs lighter per wheel anyday of the week Also with the shorter tire and lighter weight my truck feels much faster on 20's than on stockers plus I get better traction with the high performance tires, not to mention the good looks

TigerFan187

iTrader: (1)

Ok I looked back at my posts to find when I was trying to figure the weight differnce between the stock 16's and the SS 20's with tires. The SS 20's weigh 26lbs more with tires than the stock 16's with tires. So a total weight difference of 104lbs give or take with different tires. I just got sone taking my SS 20's off about 2 hours ago. I just got the LS1 in and want to feel all of it. I can only tell slight differnce but I only have like 70 miles on my new tune so there is probabaly some learning left.

'JustDreamin'

There really are three things about swapping to 20's that are detrimental to performance.

1.) Tire outside diameter: If you end up with a larger outside diameter its equivalent to changing rear end gears. If you go from 30" od tires to 32" od tires, its equivalent to going from 3.73's to 3.50's (which I know isn't a factory gear, but thats not the point).

2.) Unsprung weight: This is the weight that your bathroom scale can measure. If the wheel and tire is 15 lbs heavier, then you've got 15 lbs more unsprung weight. It will have an affect on handling, but not much affect on acceleration or braking.

3.) Rotational weight: This is the other killer for acceleration and braking. Basically the larger wheels move the weight further outside, making the rotational inertia bigger. Alot of the weight in a wheel is not in the center section, its in the rim, and as the wheel diameter gets bigger, the rim gets both longer (more circumference) and moves further from the center of rotation (I know, duh). These both act to make the wheel "feel" heavier (its a better flywheel, so to speak). This is the effect that you can't compensate for with lower profile tires, the weight is further out and there's nothing you can do.


For all out acceleration performance, I wouldn't go past 17's. 15's or 16's would be "better" in a straight line type contest. You'll notice most of the "serious" drag cars run small (15") wheels for that reason (and to make the most of wrinkle wall slicks.)

I don't know if that helps any, but figured I'd throw my $0.02 in the pot.

'Dreamin'