Wheel Size Debate - 15's or 17's
#1
Wheel Size Debate - 15's or 17's
Hey Guys,
Hoping to settle a debate. Looking to put some Cragar's on my 70' Supreme and I'm geared towards the 17's, either the traditional S/S style or the 61C style (very similar). However, I'm having an argument that 17's are not going to look right and I need to put 15's on there.
Who's got pictures of that era with either of those tire sizes so I can see what is what?
Hoping to settle a debate. Looking to put some Cragar's on my 70' Supreme and I'm geared towards the 17's, either the traditional S/S style or the 61C style (very similar). However, I'm having an argument that 17's are not going to look right and I need to put 15's on there.
Who's got pictures of that era with either of those tire sizes so I can see what is what?
#4
Tire size selection has as much affect on the look as wheel size. The problem is that these cars look best with 26.5"-27.5" diameter tires. Most low profile 17" tires are somewhat smaller that that and look lost in the stock wheelwells. With careful tire and wheel size selection, you can get the look you want.
#5
Just to give you an idea on the sizing in the pics also... I have 225/50/17s on all 4. Matched up closely to the G70 14 (front 7.5 inch and rear 9inch (looked stretched to me.) The new front wheels are 7 inch and the rear are 8 inch. Maybe a little skinny for some, but I was transporting the car and needed something I knew would fit for sure.
These tire calculations aren't fun, but the tire visualizer here at this link helped me quite a bit: https://tiresize.com/calculator/
These tire calculations aren't fun, but the tire visualizer here at this link helped me quite a bit: https://tiresize.com/calculator/
#7
#10
At any rate, there was nothing taller in a 17" that was the specific brand and tire I chose. Tire Rack has this strange policy about only selling you tire/wheel combos which they know fit your car for sure. But you can't beat the free mount and spin balance with the package.
#11
In any case, Tire Rack has a Search by Size function. If you don't tell them what car the tires are going on, they won't know. I do this with them all the time.
#12
Only if you tell them what vehicle you have. I go through this with them all the time with my crewcab dually. It's four wheel drive (actually six) and I've got oversize tires on it. If I tell them that it's four wheel drive they will not sell me only two tires, their lawyers require them to sell four (DESPITE the fact that their logic should require that I buy only SIX tires at once... ).
In any case, Tire Rack has a Search by Size function. If you don't tell them what car the tires are going on, they won't know. I do this with them all the time.
In any case, Tire Rack has a Search by Size function. If you don't tell them what car the tires are going on, they won't know. I do this with them all the time.
Here is the numbers I used and you can tell me what happened. All websites I visited to cross reference the G70-14 were showing them as 225/70/14 equivalent. When I saw the width matched and such a small height difference, I just went for it.
#13
Here is the numbers I used and you can tell me what happened. All websites I visited to cross reference the G70-14 were showing them as 225/70/14 equivalent. When I saw the width matched and such a small height difference, I just went for it.
#14
Which is why I own my own tire machine and spin balancer... Too F'n many lawyers in the world. What would happen if you tried to buy wheels and tires for a street rod?
I've found those "cross reference" tables on line to be wrong. Also, the all apparently come from the same (incorrect) source. I use the actual dimensions, not someone's equivalency. I trust my math skills more than theirs.
I've found those "cross reference" tables on line to be wrong. Also, the all apparently come from the same (incorrect) source. I use the actual dimensions, not someone's equivalency. I trust my math skills more than theirs.
#15
Well, there ya go. Of course, 225/70-14 isn't G70-14, but in any case, you can see about a 1" difference in height. That's more important than width.
#17
Yes, something is definitely up with sizing online. So I guess the question of the day is if 225/70-14 isn't the closest equivalent to G70-14, then what is? Even Year One shows it as such on their chart: http://enthusiast.yearone.com/faqs/w...version-chart/
Not that I don't believe what you say about multiple website basically copying the charts and some numbers being wrong...I can definitely see that happening because it does happen online a lot. I mean, if you have the money you can go to Coker and replace with the repro tires. But for that price I could basically get the new wheels and tires since my wheels weren't stock anyway.
What size should I have ordered in metric if I was going to stick with the 14"? Because for the other set of wheels (original look steel 14" with caps) I intend to put on this someday, I will eventually need to know.
#18
#19
I'm firmly in the minority 15" camp.
Simply for one reason; ride quality.
None of the American cars I've owned can hold a candle to quite mundane home grown offerings in grip or handling, and low profile tires don't make up the difference.
So I don't even try, savoring the magic carpet ride they offer instead.
I would until recently have added cost to my reasoning, but getting hold of 75 ratio tires is a struggle over here.
Roger.
Simply for one reason; ride quality.
None of the American cars I've owned can hold a candle to quite mundane home grown offerings in grip or handling, and low profile tires don't make up the difference.
So I don't even try, savoring the magic carpet ride they offer instead.
I would until recently have added cost to my reasoning, but getting hold of 75 ratio tires is a struggle over here.
Roger.
#20
I think either can look nice. if you run a 17" make sure you get enough sidewall. I think a lot of people go too low profile and it doesn't look good on such a bulky car. Joffroi's Supreme has a great look to it.
As far as rims, I just don't like the look of the 17" Cragar. Offset looks too high.
As far as rims, I just don't like the look of the 17" Cragar. Offset looks too high.
Last edited by droptopron; February 29th, 2016 at 10:48 AM.
#21
I built an Excel spreadsheet a long time ago to generate tire dimensions from the size. As a comparison to the G70-14s, the 225/70-14 is 26.4" in diameter and 8.86 section. If you could still buy 235/70-14s, they would be 26.95" in diameter and 9.2" section.
Moving to 17" tires, your 225/50-17s are 25.86" diameter and the same 8.86 section. 225/55-17s, which Tire Rack also sells, would have been perfect at 26.75" diameter and the same 8.86" section. This is a perfect example of why you want to start with the dimensions of the original tires and not some equivalency table.
#22
225/70-14 IS the closest CURRENTLY AVAILABLE tire size to the G70-14. 235/70-14 would have been a better choice, but no one makes those any more. That doesn't mean that 225/70-14 has the same dimensions, however. That's why I go back to the original dimensions, especially when one is comparing a completely different tire size. The actual dimensions for G70-14s are 26.8" diameter, 8.80" section width, and 6.90" tread width.
I built an Excel spreadsheet a long time ago to generate tire dimensions from the size. As a comparison to the G70-14s, the 225/70-14 is 26.4" in diameter and 8.86 section. If you could still buy 235/70-14s, they would be 26.95" in diameter and 9.2" section.
Moving to 17" tires, your 225/50-17s are 25.86" diameter and the same 8.86 section. 225/55-17s, which Tire Rack also sells, would have been perfect at 26.75" diameter and the same 8.86" section. This is a perfect example of why you want to start with the dimensions of the original tires and not some equivalency table.
I built an Excel spreadsheet a long time ago to generate tire dimensions from the size. As a comparison to the G70-14s, the 225/70-14 is 26.4" in diameter and 8.86 section. If you could still buy 235/70-14s, they would be 26.95" in diameter and 9.2" section.
Moving to 17" tires, your 225/50-17s are 25.86" diameter and the same 8.86 section. 225/55-17s, which Tire Rack also sells, would have been perfect at 26.75" diameter and the same 8.86" section. This is a perfect example of why you want to start with the dimensions of the original tires and not some equivalency table.
What also happened was that I found a particular wheel and tire brand that I liked and then the sizing basically restricted itself from there. The section width of the 17" tire I have on the 7 inch wheel is actually 9.2, according to the tire manufacturer's website, so the 8 inch rear would be 9.6 section (.2 for each 1/2 inch in wheel width) and they also show a difference of 811 revs per mile vs the calculator was showing 780. So who knows what's going on.
#24
By the way, this whole discussion should make one realize how much BS is in the "we can only sell you four tires for your all wheel drive car" argument. The differences in diameter due to air pressure variation and tread wear, not to mention the fact that tires rotate different amounts when you turn, makes that whole discussion moot.
#25
I don't know, maybe I'll just craigslist these wheels and tires. If I get $200 each out of them then it is just the price I pay for not learning enough about this before I bought. It isn't astrophysics, but it isn't the easiest topic to learn about when you basically know nothing about a tire but air goes in it and it provides traction. At least not when under a time crunch. Section width, offset, aspect ratio, etc.
Learn from what I did and either go in person locally and see and measure what you are buying or make sure you know what you are getting online.
Let's start the biddin' off!!!
Learn from what I did and either go in person locally and see and measure what you are buying or make sure you know what you are getting online.
Let's start the biddin' off!!!
#26
Wanted to share a link I found yesterday. The website says this calculator is new. The great thing about it is it actually illustrates how close the tires/wheels will be to the car's components. Take a look if you want: http://www.wheel-size.com/calc/?whee...l=25mm&scl=5mm
#27
Wanted to share a link I found yesterday. The website says this calculator is new. The great thing about it is it actually illustrates how close the tires/wheels will be to the car's components. Take a look if you want: http://www.wheel-size.com/calc/?whee...l=25mm&scl=5mm
#29
Yeah, I saw that. The problem is that the clearances you measure will be at static ride height only. The problems come when you hit a bump with the wheels turned at full lock.
#30
Well then this particular calculator may not help you get the maximum widest/tallest tire unless you know the absolute closest the tire will be when the suspension is moving, either inner or outer. Plus this calculator won't adjust for changes in section width due to changes in air pressure. But, I would guess this might help a few people to see these components graphically vs just in text, and that is the main reason why I posted it. It helped me see how it all comes together and learn a bit. Accuracy, however, I'm not responsible for.
#31
I researched this probably too much. I liked both the 15" and the 17". Had planned to toss some white letters on my 1975 olds 15" wheels w/o trim ring (equivalent to 1969 Hurst Olds wheels I believe), but ended up going with 17x8 Torque Thrust with 235/55R17. These are a very tight fit on the saggy stock suspension, but fit about perfect IMO. Getting new springs will be tricky though as I don't want to raise it too much.
Pics of both on my 69 cutlass are below.
Pics of both on my 69 cutlass are below.
Last edited by clajohol; March 3rd, 2016 at 01:13 PM.
#32
Also a quick note, my 17s do rub slightly when turning and backing up at the same time. No problems on the road though.
As for tire size, I agree. I found this out recently when buying new truck tires. The xxx/xxRxx number does no necessarily give the exact physical dimensions of a tire.
As for tire size, I agree. I found this out recently when buying new truck tires. The xxx/xxRxx number does no necessarily give the exact physical dimensions of a tire.
#33
I researched this probably too much. I liked both the 15" and the 17". Had planned to toss some white letters on my 1975 olds 15" wheels w/o trim ring (equivalent to 1969 Hurst Olds wheels I believe), but ended up going with 17x8 Torque Thrust with 235/55R17. These are a very tight fit on the saggy stock suspension, but fit about perfect IMO. Getting new springs will be tricky though as I don't want to raise it too much.
Pics of both on my 69 cutlass are below.
Pics of both on my 69 cutlass are below.
#35
When it comes to my car, I just can't wait to see how it looks with the original style steel wheels and caps. I like that look better than any larger wheels that I've looked at. Just something about the simplicity of it all. Does anyone know for sure how I can determine what brand tire needs to be on this, as in what it originally had from the factory? I know Coker sells the repros.
#36
When it comes to my car, I just can't wait to see how it looks with the original style steel wheels and caps. I like that look better than any larger wheels that I've looked at. Just something about the simplicity of it all. Does anyone know for sure how I can determine what brand tire needs to be on this, as in what it originally had from the factory? I know Coker sells the repros.
Roger
#37
I'm a fan of stock wheels and lowered suspension. I'm also a fan of upgraded brakes, lowered/aftermarket suspension and better handling. So I went with 18's in a classic 5-spoke style. 17's needed spacers to clear the brakes, these 18's fit perfect.
255/45 front and 285/40 rear:
255/45 front and 285/40 rear:
#38
I'm a fan of stock wheels and lowered suspension. I'm also a fan of upgraded brakes, lowered/aftermarket suspension and better handling. So I went with 18's in a classic 5-spoke style. 17's needed spacers to clear the brakes, these 18's fit perfect.
255/45 front and 285/40 rear:
255/45 front and 285/40 rear:
#40
Have to ask; what rims are those? Doesnt think ive seen those surfing through various sellers.
IMO only few aftermarket rims will fit our cars, and i think those are ones.
Torq Thrusts ofc will fit anything, problem is only that they are presented on 9/10 cars there or atleast it feels so, and cant blame them. Just want something different.
IMO only few aftermarket rims will fit our cars, and i think those are ones.
Torq Thrusts ofc will fit anything, problem is only that they are presented on 9/10 cars there or atleast it feels so, and cant blame them. Just want something different.