Need some advice Luke (and others)

[JTS]

I have decided that I am going to upgrade the wheels and tires on my black '99 4-door/4x4 Tahoe. These wheels will only be for May-October. I had initially thought that I would go with 18"s and use a tire size of 285/60-18 but I have been looking on the Web for deals and I have found more good prices on 20"s than I have on 18"s. I had initially thought that 20"s would be too flashy for me, but I'm not sure anymore. What would a nice wide tire size be for 20"s?

I want an aggressive, "muscular" stance to the truck but I don't want to raise or lower it, i.e., aggressive, but not anything too crazy. I don't want to worry about any rubbing or any other problems. I also don't want to have to re-cal the speedo or the ABS or any of that.

I know I need 6-5.5 bolt pattern and I think 18x8.5 is the correct wheel (or 20x9?). If I want the wheels to stick out a tiny bit from the wheel wells, am I looking for a negative offset? I don't understand the BSM parameter. Is hubcentric a necessary feature?

I'd like to get this done as soon as I can, so any help is appreciated. Thanks.

[JayMan]

I'm not familiar with your car (i'm an aussie). But whats the size of the stock wheels & tyres? from that ya can work out what size you should go to keep ya speedo accurate. Then its just a matter of finding out if there are any laws or regulations for your area that limit your wheel size (australia is pretty strick on car mods, dunno what its like elsewhere).

As far as getting the right offset, i wouldn't have a clue what offset you would need...

Have ya got a pic of your car? Are there any styles of wheels you like or are you looking for suggestions too?

JayMan

[JTS]

My truck came with 245/75-16s and I replaced those with some nice M+S 275/70-16s. I know that overall diameter should be close to OE in order to keep speedo and ABS close to spec. I don't know how "close" is close enough though. According to my calculations,

245/75-16 (Stock): 245x.75x2=367.5 + 406.4 (16") = 773.9 = 30.47 inches
275/70-16 (Current):275x.70x2=385 + 406.4 = 791.4 = 31.16 inches
275/60-17: 275x.60x2=330 + 431.8 = 761.8 = 29.99 inches
285/60-18: 285x.60x2=342 + 457.2 = 799.2 = 31.46 inches
295/75/16: 295x.75x2=442.5 + 406.4 = 848.9 = 33.42 inches
295/65/16: 295x.65x2= + 406.4 = 31.09 inches
295/50/16: 295x.50x2= + 406.4 = 27.61 inches

I haven't looked into 20" tires yet because I didn't think I was going to go that big. Now I'm not sure.

Here are a couple of pics of a Tahoe with a tire set up that I like. My truck is the same except solid black, with no moulding or badges. What do you think the size of the wheels and tires are?

[JTS]

Side View

[TexasF355F1]

You could always get like a 305/45/20 tire. I think that would give you a really nice ride with a nice look. Once you get em please post pics!

[Cy@tirerack]

Best choice for you would be running 305/50-20's. At 31.9" overall diameter this size is only .7" bigger than your current tire size so there would only be 2.8% speedometer error. Your speedo would underestimate your actual speed by 2.8%. We recommend staying within 3% especially with ABS/traction control equipped vehicles.

We have test fit this size so there will no rubbing issues as long as the truck has not been lowered.

There are a fair amount of tires available in this size so pricing is fairly decent ranging from $149 to $316 before shipping.

Your stock wheel has an offset of 40 mm. The offsets on our 20" wheels range from 10 to 22 mm. In general terms, the smaller the offset the more "out" the wheel is, the larger the offset the more "in" the wheel is. The smaller offsets help fill out the wheel well and make the wheel look better unless you go too small of an offset the makes the wheel stick out.

It's difficult to tell the exact size of the wheels pictured, but judging by the amount of the fender gap, figure 18 or 20.

[JTS]

Thank you Cy, Texas and Jay. Much appreciated.

I'll post pics once it's done.

[mojosc]

The Tahoe can hold a pretty good size wheel tire combo. If you go with 20's go with a 9.5 or a 10. That will allow you to run a 285, 295, or a 305. That's plenty of tread width for stability. Your offset needs to be 10mm to 20mm (positive). This will insure the wheels won't rub on the inside or stick out past the fender well.

Mojo

[JTS]

The Boss 306s that I like come in 20x8.5 only.

If I want to go with 305/50-20, is this wheel now out of the running?

What's the math for the relationship between tire width and minimum wheel width?

Thanks.

[Cy@tirerack]

There's no strict formula but for most 305/50-20 tires you can run a rim width from 8.5 to 11 inches.