15x8 with -19 or -27 offset.
Thread Starter
Junior Member
Joined: Mar 2021
Posts: 2
Likes: 0
15x8 with -19 or -27 offset.
I'm confused.
I'm looking at some 15x8's. If I trust Discount Tires website it tells me that 15x8 with a -27 offset doesn't fit my truck but a 15x8 with a -19 offset is just fine.
I have a 1996 F150 Supercab, 2WD with the 5.0 (not that the engine really matters). I plan to level the truck, maybe a small lift in the future. I want to put 32x11.5's on it because these 235's seem so tiny. I currently have the stock polished 15x7.5's with the 10 hole design (is there a name for these?). From what I understand these are a zero offset (I have not pulled off a wheel to measure, but I've scoured this site and that is what keeps coming up).
I also understand I may, or may not get some rubbing with the tire size I am interested in. But according to https://tiresize.com/wheel-offset-calculator/ the negative -27 should just push the wheel and tire further out from the radius arm. Wouldn't that be in my benefit to keep it from rubbing?
Sorry, this is my first truck (inherited from the wife's grandpa when he passed) so wheel fitment is a bit different from the cars I've put rims on in the past (backspacing for instance).
I've been lurking here for about half a year and usually can find my answers just by reading, but I don't see this particular setup in question. Thanks in advance.
I'm looking at some 15x8's. If I trust Discount Tires website it tells me that 15x8 with a -27 offset doesn't fit my truck but a 15x8 with a -19 offset is just fine.
I have a 1996 F150 Supercab, 2WD with the 5.0 (not that the engine really matters). I plan to level the truck, maybe a small lift in the future. I want to put 32x11.5's on it because these 235's seem so tiny. I currently have the stock polished 15x7.5's with the 10 hole design (is there a name for these?). From what I understand these are a zero offset (I have not pulled off a wheel to measure, but I've scoured this site and that is what keeps coming up).
I also understand I may, or may not get some rubbing with the tire size I am interested in. But according to https://tiresize.com/wheel-offset-calculator/ the negative -27 should just push the wheel and tire further out from the radius arm. Wouldn't that be in my benefit to keep it from rubbing?
Sorry, this is my first truck (inherited from the wife's grandpa when he passed) so wheel fitment is a bit different from the cars I've put rims on in the past (backspacing for instance).
I've been lurking here for about half a year and usually can find my answers just by reading, but I don't see this particular setup in question. Thanks in advance.
Senior Member
Joined: Jul 2007
Posts: 3,806
Likes: 481
From: Cape Girardeau MO
A belated welcome to the site!
For starters, the stock 235/75 tire should be about 28.9 inches tall and 9-1/4 inch wide, as compared to the spec 32 inch tall and 11.5 inch wide tires you're looking at.
Not knowledgeable enough to be more than a simple observer on this wheel stuff, but seems that the difference between the -19 and -27 (millimeters) is 0.31 inches, or about 5/16 inch. Maybe getting flagged on the tire sites because of the wheel bearing side-load - the FWD cars need the positive offsets for the bearing design loads/thrusts, IIRC, perhaps the same applies to the other direction for conventional arrangements...?
FWIW, my '89 4WD looked good with 15x8 with 31x10.50R15, there used to be a very general rule that the wheel width needs to be within 2 inches of the tire width so as not to have that balloon / doughnut tire look, so following, your desired 32x11.5 may be better 'looking' with a 15x10 wheel. If you know a friendly tire shop, may be worth trying a couple sizes out on the desired wheels to see what is acceptable to you. If your stock wheels are indeed 7.5 inch width, seems that going to only an 8 inch width would be a waste of money...? May give a 30x9.5 a look for grins to see if it suits the look you're after, plus should be able to get away with using the current rims.
Suggest to be careful - too much negative offset may result in tire rubbing the fender on deep suspension bounces, if set too far out - until the levelling is installed.
For starters, the stock 235/75 tire should be about 28.9 inches tall and 9-1/4 inch wide, as compared to the spec 32 inch tall and 11.5 inch wide tires you're looking at.
Not knowledgeable enough to be more than a simple observer on this wheel stuff, but seems that the difference between the -19 and -27 (millimeters) is 0.31 inches, or about 5/16 inch. Maybe getting flagged on the tire sites because of the wheel bearing side-load - the FWD cars need the positive offsets for the bearing design loads/thrusts, IIRC, perhaps the same applies to the other direction for conventional arrangements...?
FWIW, my '89 4WD looked good with 15x8 with 31x10.50R15, there used to be a very general rule that the wheel width needs to be within 2 inches of the tire width so as not to have that balloon / doughnut tire look, so following, your desired 32x11.5 may be better 'looking' with a 15x10 wheel. If you know a friendly tire shop, may be worth trying a couple sizes out on the desired wheels to see what is acceptable to you. If your stock wheels are indeed 7.5 inch width, seems that going to only an 8 inch width would be a waste of money...? May give a 30x9.5 a look for grins to see if it suits the look you're after, plus should be able to get away with using the current rims.
Suggest to be careful - too much negative offset may result in tire rubbing the fender on deep suspension bounces, if set too far out - until the levelling is installed.