Will this tire/wheel size work

[44boggers]

I know there are a million threads on this and I have gone through them all. I have done measurements on my truck but I just want to double check with them masses.

I have a 5/7 static drop. Will this tire/wheel combo fit?

Thank you in advance

Paul

Front: 8.5x20, Tire: 255/40R20 Backspacing: 5.25"
or
8.5x20, Tire: 255/45R20 Backspacing 5.25"

Rear: 10x20, Tire: 295/40R20 Backspacing: 5.5"
or
10x20 , Tire: 305/45R20 backspacing: 5.5"


I would prefer to us the 305 tire in the rear if it will work. Please let me know from your experiences.

Thanks

[SKR]

I'd say they should fit. I'm running the same size wheels, with 245/40 in the front and 315/35 in the rear. I don't think there would be any issue going to a 255/40 in the front. Not sure about a 255/45 though, that might be getting too tall. For the rear, 315 is as wide as I'd go but taller shouldn't be an issue. A 305/45 is over 2" taller than a 315/35 though.

245/40ZR20 and 315/35ZR20 fit my truck with a 5/6 drop without rubbing anywhere.

[44boggers]

Originally Posted by SKR

I'd say they should fit. I'm running the same size wheels, with 245/40 in the front and 315/35 in the rear. I don't think there would be any issue going to a 255/40 in the front. Not sure about a 255/45 though. For the rear, 315 is as wide as I'd go but taller shouldn't be an issue. A 305/45 is over 2" taller than a 315/35 though.

WHat backspacing are you running? Do you have any pics of your truck? Did you have to modify your fenders at all for fitment?

[SKR]

Originally Posted by 44boggers

WHat backspacing are you running? Do you have any pics of your truck? Did you have to modify your fenders at all for fitment?

Same backspacing as you want to run, 5.5 rear, 5.25 front. I haven't had to make any adjustments to the fenders to get them to fit.

[44boggers]

Originally Posted by SKR

Same backspacing as you want to run, 5.5 rear, 5.25 front. I haven't had to make any adjustments to the fenders to get them to fit.

Truck looks great. After seeing your set up i am leaning towards 255/40-20 and 315/35-20. Just a couple questions.

1.How much room do you have between the tire and the fenders front and back?

2. Do you think it would be possible to run a 5" backspacing in the front with a 255/40?


Thanks for you insight.

Paul

[SKR]

The rear is about an inch from the outside sidewall to the fender, and less than that, maybe 3/4 of an inch from the inside sidewall to the fender.

The front has more room. Probably an inch and a half on the outside, and lots on the inside.

It's tough to measure because I don't have a way to get the truck off the ground to get underneath it.

I think a 255/40 probably would fit with a 5" BS. I think there's room there to take the 1/4 inch of backspacing and the 10mm of extra tire. I don't know though.

The only reason I went with 245/40 in the front was because that's all that was in stock at the time. I ordered 275/35 but they didn't come, and we weren't sure if they would fit anyway. So we put the 245s on. Next time I think I'll try a 275/35 though, and I might go down to a 305 in the back.

[44boggers]

Originally Posted by SKR

The rear is about an inch from the outside sidewall to the fender, and less than that, maybe 3/4 of an inch from the inside sidewall to the fender.

The front has more room. Probably an inch and a half on the outside, and lots on the inside.

It's tough to measure because I don't have a way to get the truck off the ground to get underneath it.

I think a 255/40 probably would fit with a 5" BS. I think there's room there to take the 1/4 inch of backspacing and the 10mm of extra tire. I don't know though.

The only reason I went with 245/40 in the front was because that's all that was in stock at the time. I ordered 275/35 but they didn't come, and we weren't sure if they would fit anyway. So we put the 245s on. Next time I think I'll try a 275/35 though, and I might go down to a 305 in the back.

Thanks!
Why would you go down to a 305?
If you have over an inch of clearance in the front and i went with a 255 with a 5" backspacing, am I correct in my math. at 255 is about .5" wider than a 245. So now I would be down to say .75" and then .25" less in back spacing. I am down to .5" of clearance. Would that be correct?

[SKR]

I think your math is right, you'd be left with 0.5". Maybe that's too close. I don't know how much clearance you need. A 255/40 would be a little taller than my 245/40 too, so maybe where the width would clear, the height wouldn't allow it.

My reasoning for going down to a 305 is that I remember it being easier to find tires. It was a while ago that I was tire shopping. Over a year ago now. But I remember it being hard to find a tire that met all these conditions: had sizes in 305 or 315, and were around 28-29" tall, and also were available in a 245-275, and were shorter than what the rears would be, and were available almost immediately because I was running out of good weather, and weren't outrageously expensive. Nitto Invos were the only ones that fit that criteria, and I don't mind the performance but I don't like the look.

If I can find a good 265 or 275 to go in the front, and a 315 to match it in the rear, I'll stay with 315. I just might have to go down to a 305, which wouldn't be the end of the world. I think you should always go with the widest tires you can though. It just looks better to me.

[44boggers]

Originally Posted by SKR

I think your math is right, you'd be left with 0.5". Maybe that's too close. I don't know how much clearance you need. A 255/40 would be a little taller than my 245/40 too, so maybe where the width would clear, the height wouldn't allow it.

My reasoning for going down to a 305 is that I remember it being easier to find tires. It was a while ago that I was tire shopping. Over a year ago now. But I remember it being hard to find a tire that met all these conditions: had sizes in 305 or 315, and were around 28-29" tall, and also were available in a 245-275, and were shorter than what the rears would be, and were available almost immediately because I was running out of good weather, and weren't outrageously expensive. Nitto Invos were the only ones that fit that criteria, and I don't mind the performance but I don't like the look.

If I can find a good 265 or 275 to go in the front, and a 315 to match it in the rear, I'll stay with 315. I just might have to go down to a 305, which wouldn't be the end of the world. I think you should always go with the widest tires you can though. It just looks better to me.

It seems like a 275/40 could also fit up front with a 5.25" backspacing. Can you fit that wide of a tire on a 8.5" wheel?

[SKR]

I didn't think of that, but they should physically fit. There would be a little sidewall bulge there. Now that you mention it, that was another reason I had for going to a 305.

My 315s are 2.4" wider than the 10" wheels they're on. A 275 would be 2.3" wider than an 8.5" wheel. Both would have 110mm of sidewall. So if a 315/35 fits on a 10" wheel, a 275 should fit on a 8.5" wheel. I have no knowledge, experience or science to back that up though.

Edit: I can't believe no one else is chiming in. These are pretty common wheel sizes I thought, so I can't be the only one with opinions on what fits and what doesn't.

[44boggers]

I hear ya, Seems like a lot of people run a 315 on a 10" rim.Your rear tire/wheel set up doesnt appear to have much bulge to them.

I think I will go with the 255/40 and 315/35 and if I need to use a 1/4 spacer in the front if i want to get the wheels more flush. easier to add then take away.

[BabyBlue]

Here is my step side prior to blowing it apart with 20x10 with 295/40 rear 5.5BS and the front was 5" BS but were 18x9 with 245/45 if I remember correctly. I ran factory inner fenders and never rubbed. Those wheels and tires lifted the truck up higher than it was with my first set of wheels but overall the drop was a 5/7 but kind of pushed closer to 6" drop in the front...never rubbed and I had plenty of room especially in the back. At least an 1" either side if I remember correctly. I narrowed the rear after that by 1.5" either side to change the offset of the wheels. Although I am also guessing you have a short wide and not a stepper.

[44boggers]

Originally Posted by BabyBlue

Here is my step side prior to blowing it apart with 20x10 with 295/40 rear 5.5BS and the front was 5" BS but were 18x9 with 245/45 if I remember correctly. I ran factory inner fenders and never rubbed. Those wheels and tires lifted the truck up higher than it was with my first set of wheels but overall the drop was a 5/7 but kind of pushed closer to 6" drop in the front...never rubbed and I had plenty of room especially in the back. At least an 1" either side if I remember correctly. I narrowed the rear after that by 1.5" either side to change the offset of the wheels. Although I am also guessing you have a short wide and not a stepper.

Your truck is very nice man. Thanks for the pics and info. So the 255/45 with 5.25" should end up close to what your front set up is, maybe even a little tighter.

And yes I have a short wide.

[44boggers]

I am planning on using a Vossen VS1 wheel. They told me they do not have the offset I need in a 10" wheel but they do in a 10.5" wheel. Any reason I couldnt run a 10.5" wheel? I think I should still have enough room.

Here is my math. I measured from the hub to the bedside wheel well lip, 7". First off does that sound about right?

So if I run a 10.5" wheel which actually should measure out to about 11.5", then divide that by 2 that gives me 5.75", so a 0 offset. This leaves me with theoretically 1.25" of space between the rim and the wheel well lip. If I run the 10.5" wheel with a 5.5" backspacing (-6mm offset) I should be left with 1" of clearance. So that seems all fine.

How much tire bulge would I have with a 315/35 tire on a 10.5" have? More than 1 inch?

To the inner wheel well I measure from the hub 6.75", so with all the math above that should leave me with roughly 1" as well.


Does this all seem correct and does anyone have any contradicting numbers regarding hub to wheel well measurements?

Thanks!

[44boggers]

Ok this is what I am able to use with the Vossen VFS1 wheel.

Rear: VFS1- 20X10.5 - ET+5 (5.95” backspacing)
Front: VFS1- 20X8.5 - ET+15 (5.35” backspacing)

Tires: 255/40/R20 and 315/35/R20


The back is a bit to much backspacing, but I could run a .5" spacer and it should sit nice and flush.

Here is the wheel for reference.

Is there any reason you guys see why this set up would not work?

[Loco83]

Originally Posted by BabyBlue

Here is my step side prior to blowing it apart with 20x10 with 295/40 rear 5.5BS and the front was 5" BS but were 18x9 with 245/45 if I remember correctly. I ran factory inner fenders and never rubbed. Those wheels and tires lifted the truck up higher than it was with my first set of wheels but overall the drop was a 5/7 but kind of pushed closer to 6" drop in the front...never rubbed and I had plenty of room especially in the back. At least an 1" either side if I remember correctly. I narrowed the rear after that by 1.5" either side to change the offset of the wheels. Although I am also guessing you have a short wide and not a stepper.

Beautiful truck, love that color, reminds me of my cruising days back in the late 70's/80's, back in the day wire wheels were the ticket

[BabyBlue]

Originally Posted by 44boggers

Ok this is what I am able to use with the Vossen VFS1 wheel.

Rear: VFS1- 20X10.5 - ET+5 (5.95” backspacing)
Front: VFS1- 20X8.5 - ET+15 (5.35” backspacing)

Tires: 255/40/R20 and 315/35/R20


The back is a bit to much backspacing, but I could run a .5" spacer and it should sit nice and flush.

Here is the wheel for reference.

Is there any reason you guys see why this set up would not work?

10.5" wheel with the 6" backspacing would be pretty darn close. For the 315 you would be looking at a decent bulge but not excessive.

10.5" is the minimum width for those tires and each manufacturer is a little different. I personally run Michelin's on most of my vehicles. Below is the info from Tirerack.

315/35ZR20
(110Y) XL
K2 Ferrari

300 AA A 2,337 lbs 50 psi 10/32" 34 lbs 10.5-12.5" 11" 12.6" 11.6" 28.7" 726 FR

Attached is a pic I found of some Vossens for a Camaro 315 on a 20x10.5

Worst case scenario you could run a spacer like you said for a little while but since you have a SWB, they have stock looking tubs that are slightly wider....I think 1-2" wider.

[44boggers]

Originally Posted by BabyBlue

10.5" wheel with the 6" backspacing would be pretty darn close. For the 315 you would be looking at a decent bulge but not excessive.

10.5" is the minimum width for those tires and each manufacturer is a little different. I personally run Michelin's on most of my vehicles. Below is the info from Tirerack.

315/35ZR20
(110Y) XL
K2 Ferrari

300 AA A 2,337 lbs 50 psi 10/32" 34 lbs 10.5-12.5" 11" 12.6" 11.6" 28.7" 726 FR

Attached is a pic I found of some Vossens for a Camaro 315 on a 20x10.5

Worst case scenario you could run a spacer like you said for a little while but since you have a SWB, they have stock looking tubs that are slightly wider....I think 1-2" wider.

Yeah i think with a .5" spacer it should work. The dealer will deliver the wheels and tires directly to me when they are ready and we will measure for spacers and then he will send me the correct wheel spacers.
Thanks guys for all of your help

[4u2nv]

This may help some

[4u2nv]

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