slpsilverado

iTrader: (1)

I did a search, with no luck. Don't hate.

My truck (in sig) has 3.23s and 245/70/17 factory wheels (which are 30.5 inches tall). I have found a set of SS 20s (275/55/20) locally (they are 31.9 inches tall).

I want to put these wheels on, but don't have the time for a gear change (tax season + CPA = live at work) and I want to wait until I have a few more mods before I get a "full" tune. And I know that putting on taller tires drops cruising RPMs.

I don't want my vehicle to be a . Can someone recalibrate my speedo and RPMs to mimic my current setup? Or do I HAVE to have gears (like 3.73s) to get my RPMs back up?

dlt76028

iTrader: (13)

you need to sell the tires and put a smaller size on there like 275/45/20 or something around 30". 275/55/20 look like giant 4x4 tires on a 2wd.

slpsilverado

iTrader: (1)

275/55/20 was the factory OEM size for the Silverado SS, was it not? I think they look good.

dlt76028

iTrader: (13)

heres 275/55/20 on a 2wd with 2" drop shackle in rear. it's a freaking 32" tall tire and was goofy as hell, and rubbed in the front.

slpsilverado

iTrader: (1)

Interesting. Do Silverado SS's all have wheels that rub? Or is the wheel well different?

Can someone post up pics of this wheel with 275/45/20? I've seen them on here, but having trouble with the search. Also, more pics of 275/55/20 up close would be nice.

dlt76028

iTrader: (13)

These pics show how big the tires are. heck they're bigger then the tires on the 3/4 ton next to it.

https://www.performancetrucks.net/fo...d.php?t=466445

1Bear

iTrader: (1)

The only downside I see to doing what the guys are telling you to do is the shorter sidewalls will result in an ever so slightly harsher ride and while it’s real, I doubt it’s anything you will really notice. Your truck will respond well to the shorter tires from the improved gearing and slightly lighter weight. You will appreciate the fitment and looks of the shorter tires as well. As you stated, the 275/55/20 was the factory OEM size for the Silverado SS, but the torsion bar suspended trucks also had a little bit higher factory ride height than the regular 2WD ½ Ton trucks such as yours. On a side note, all the AWD SS trucks came equipped with 4.10 gears, while the 2WD versions came with 3.73’s and as such later when your able, I would suggest a gear swap for yours to maximize performance. While I’ve always liked the looks of the factory SS wheels, you have to remember being cast wheels, they are fairly heavy.

Having an AWD truck myself, I fell into the same trap of wanting a wheel/tire combination to fill in the wheel-wells at the higher ride height and originally had the Joe Gibb’s 20” wheels, which I really liked due to the center of the wheels having a real nice color match with the pewter color of my truck. The downside was they were particularly heavy, which had a negative impact on acceleration and especially braking. To combat the taller wheel/tire combination I went with 4.56 gears and to help slow her down, I went to the Z06 6-piston calipers and 15” Baer rotors, but then the Gibb’s wheels with their really curved spokes didn’t want to clear the brake calipers without using spacers. I ended up going with an even larger set of 22” Moto-Forge wheels to get a proper fitment over the larger brakes and while being a forged wheel they are actually lighter than the smaller 20” cast wheels, I still preferred the looks of the Gibb’s wheels. I’m also stuck with having to have identical sized wheels and tires being AWD. It’s a viscous circle of adding something, only to find out now you need to add something else. Had my truck been a RCSB 2WD, there is no doubt I would have went a different direction of more a serious looking street performance truck with a lower ride height and mismatched sized wheels/tires, being the lightest combination I could afford for the best overall performance.

viciousknid

iTrader: (8)

You either take it to the dealer to be recalibrated or get a custom tune and have the tuner change it. Or just go to a local tuner and have them change it.

00ChevyScott

iTrader: (10)

FYI your RPMs cannot be "recalibrated". Your speedo can be changed to display the correct speed, but at 70 mph your RPMs will remain the same. I don't know if maybe I'm reading what you posted wrong, but the RPMs can only be affected by tire size or gear change.

viciousknid

iTrader: (8)

Missed that part. As Scott said. the RPM's is how fast your engine is spinning which has nothing to do with tuning. That is only effected by gears or tire size. Bigger tires mean less rpm, smaller tires means more rpm. The only calibration that is done is making your speedometer correct based on the RPM of the TIRES