Have fat-pig tires been discussed already?

So, I need some street-class legal tires for the Moostang.

Running 17x8s on all four corners, I'm mainly looking at 245/45s.

Problem is, every comparison article is done on a 53 lb Honda Civic, and I'm sure that doesn't translate to a 35k lb Mustang convertible (that figure's probably off by a factor of 10 ).

Car does get driven on the street occasionally, but it's mostly just drive to AX, race AX, drive home.

I'd like to stick to $150/tire or less, need to stay at or above 140 treadwear.

Currently I'm thinking about Kumho ECSTA XSs, Direzza Star Specs, and Federal 595s (I know, what are those doing on the list?). Or maybe the Hankook Ventus Evo whatever-the-heck-they-are. That most recent GRM mentioned Maxxis had a new UHP tire... maybe some of those?

I might be selling off one of my other rigs, which could mean that the Mustang becomes my primary vehicle, so I won't be shaving anything (well, except for... nvm, this is polite company )

So, thoughts?

Oh, anyone know of some lightweight wheels that are the right backspacing for Mustang? I'm getting rid of my 17x9 BBS RXs because they're just too deep and I hate running spacers. If I could find some cheap, light wheels that fit... If I don't upgrade my brakes, I can go down to a 15" wheel.

I've got an 1995 Mustang GT Conv. in my garage and I'm looking at a set of Enkei RFP1's from Vivid Racing; 17x8.5, ET30 offset. Summer tires will probably be Firestone Indy 500 Wide Oval's, 245-45-17.

I haven't purchased anything yet so this is just on paper. The Enkei's are listed on Vivid's website as weighing 16.0 pounds each in that size and are ~$230 ea + shipping. The tires are about $125 ea from Tire Rack.

I don't know if this helps or not but that's what I'm looking at, 100% street usage. There have been issues with the title (long story, not happy) so until that situation is corrected I'm not spending a dime on the car.

Hrm, that's about a 5.5" backspace... I think that's actually just about right for what I'm doing. I think my BBSs are a 6.25" backspace.

FWIW, I hate offset as a way of stating backspace. "+40" only means something if you know how wide the wheel is, backspace requires no other knowledge. It's like metric tire sizes vs SAE, the SAE is more informative as to how big the tire actually is, with the metric sizing you have to crunch the numbers. Sizing should never be spec'd in relative values.

don't know anything about the Federals ... the others are all good choices.. speaking as one of the 53 # Honda guys I just put on some Toyo R1R's this past weekend and have NEVER experienced that kind of grip on an a-x course in my life (including when I ran DSP on V710's in the Integra)... not sure how they hold up under the heavier car [seems all the faster ST / STS (light weight) cars run on the Toyos ]

Huh, TireRack has the Hankooks for $100/tire, and they've got the MIR. That might just be winner-winner-chicken-dinner right there.

I've had a set of the first Star Specs for ages - I can't kill 'em.

I've used them for driving to events in a still-streetable-but-just e36 M3. I've autocrossed them, used them in the rain and dry at Summit Point, Shenandoah, VIR and NJMP.

They're still going strong at 1/3 tread depth though grip has fallen off. They've had a bazillion heat cycles though.

I'm buying another set for the M3 and set for the Miata. It's not even a question.

I've ran starspecs (technically non-starspec D1's) on my 96 cobra for several autocross seasons, they performed flawlessly, just buy them, you absolutely won't be sorry...

I've had Federal SS595 RSs on a Miata after the Hankook RS2 I wanted as a cheapish track & DD tire had sold out. They were pretty good - not as good as Toyo R888 but rather good for the price.

Of course I have no idea how well they work on a Mustang.

Something I thought about later; you and I are both talking about running a 245mm wide tire. I know that's tread and the numbers are a little fuzzy from make to make, but every time I look at these tire specs I see something like 7.5" to 9" wide wheels as the recommendation. Unless there's a chance that a guy would take that 245 to 255 in the future, is there a reason to not get an 8" wide tire instead? I can't afford to buy these dumb things twice...

pres589 wrote: Something I thought about later; you and I are both talking about running a 245mm wide tire. I know that's tread and the numbers are a little fuzzy from make to make, but every time I look at these tire specs I see something like 7.5" to 9" wide wheels as the recommendation. Unless there's a chance that a guy would take that 245 to 255 in the future, is there a reason to not get an 8" wide tire instead? I can't afford to buy these dumb things twice...

Okay, I'm not 100% sure on what you're asking, but I think the answer might be in the "formulas" for Tire width relative to wheel width.

{commence brain dump!}

Note: any tire sizes below assume that the manufacturer's stated section width is dimensionally accurate. For brands known to run wide or narrow, compensate accordingly.

Most manufacturer's recommend a tire that's 120% of the wheel width. So, for an 8" wide wheel (203.2mm), 120% is 9.6" wide (243.8mm) aka 245.

What I've seen as acceptable range for is anything from 100% to 125%. So, for that 8" wheel, we're talking anything from a 205 to a 255. I've heard of drag racers putting tires that are more like 130% on the rears, but I think that they're being silly to do so. I've seen autocrossers have good results putting the widest tire they can fit on their wheels, but I think this is a very specific instance that's working within a restrictive ruleset, not an optimal setup.

My understanding is that for most performance driving, you really want something more like 110-115%. (for the example 8" wheel, that's a 225-235). Endurance racers apparently prefer something around 95% of the wheel width (according to the Thunderhill tire guys).

Narrower tire sacrafices traction patch size for increased responsiveness. It gives the tire a higher effective spring rate. Wider tire sacrifices responsiveness for more overall grip, and gives the tire an effectively lower spring rate.

So, I'm figuring 245 will be best for my application, because well, I'm used to running 255s on a 9" wheel and don't want to give up that traction patch, but I also don't want to have big fat sloppy sidewalls. Sticking with 120% seems to be a happy medium between responsiveness and grip.

Does that help answer your question?

I have autoxed my M3 on the Federal SS595s many times. They were really cheap, and I was simply looking for a day-to-day tire as I had a set of R888s for the track and autox use. But, there were times when I didn't feel like swapping tires -- and ended up running the Federals. They were better than decent, and the car actually felt better on them then the R888s during autox (probably because the suspension on the M3 is somewhat tired).

They've worn well, too. For what I paid I can't complain.

My next tires for that car will be the Star Specs, however -- they seem like the best all-arounder right now.

"Does that help answer your question?"

Yeah, I had put together similar reasoning for this, but figured I would ask to see what your thinking was.

I don't have much to offer, but the Star Spec is THE tire that everyone that's competitive uses in Chump Car.

I don't understand why you are not running 255/40r17? It goes on an 8" wheel all day long.

In reply to John Brown:

Threadjacking this slightly, I'm going with the 245/45/17 because I don't want the contact patch to get too wide & too short. Also the tire costs start to go up further with the 255.

ReverendDexter wrote: Hrm, that's about a 5.5" backspace... I think that's actually just about right for what I'm doing. I think my BBSs are a 6.25" backspace. FWIW, I hate offset as a way of stating backspace. "+40" only means something if you know how wide the wheel is, backspace requires no other knowledge. It's like metric tire sizes vs SAE, the SAE is more informative as to how big the tire actually is, with the metric sizing you have to crunch the numbers. Sizing should never be spec'd in relative values.

What? They measure the same thing in different ways.

The correlation of the mounting surface to either the center of the wheel (ET) or to the bead on the rear of the wheel (Backspace).

Knowing that your wheels have 6.25" of backspace, without knowing the width, is just as worthless as knowing your wheels are ET +43 without knowing the width.

z31maniac wrote: Knowing that your wheels have 6.25" of backspace, without knowing the width, is just as worthless as knowing your wheels are ET +43 without knowing the width.

Nope. If I know the backspace, I know immediately if the wheels will fit on my car or not (assuming that the bolt pattern is right, of course). I may not know if they'll be a good fit, but I know if I'll rub. Case in point: I know for a fact that anything with more than 6" backspacing won't fit on my car. You tell me a wheel has 5.5" backspace, I know it'll at least fit on there . Doesn't matter if it's a 10" or a 6" wheel, I know it's not gonna hit on my control arms at full lock. Contrast that with a "+40", where it depends if it's wider or narrower than about 8.5 inches (which is directly applicable, as I run either an 8 or 9 inch wheel).

Maybe if we expressed wheel widths in metric, offset would be sensical, but we don't, so it's unnecessarily esoteric. Given the measurements of a wheel, I shouldn't THEN have to do math to see if it'll fit. The measurement should tell me that immediately.

You only know that it's going to fit on the inside. You dont know if the fender is going to cut your tire on compression or if you can turn the wheel lock to lock without running the tire into the front and back of the wheelwell.

Its still only half the story.

Vigo wrote: You only know that it's going to fit on the inside. You dont know if the fender is going to cut your tire on compression or if you can turn the wheel lock to lock without running the tire into the front and back of the wheelwell. Its still only half the story.

You mean there is a fitment difference between a 6" ET51 wheel and a 10" ET0 wheel?

But OP was trying to make a generalization about it based on a case study.

Vigo wrote: You only know that it's going to fit on the inside

Which is more than I know from seeing an offset number.
Something > Nothing.

LOLZ.

Tire Rack has 255/40R17 Hankook Ventus RS-3 in stock for $121.00

In reply to John Brown:

How much is the 245/45/17?

There isn't one ;)

Hankook Ventus RS-3

In reply to ReverendDexter:

What'd you end up doing on this? I'm calling around, having just received the title to the car, and Tire Rack doesn't recommend the 8.5" wide wheel with an ET 30 offset. They do carry an 8" wide with that offset and it is a "recommended fitment" to the car and there is not alternative offset for the 8.5".

I'm worried that I'll be ordering in a lot of wheels that don't fit the car all of the sudden. Vivid only had the wheel with the chrome finish which I don't want (and with a price premium which disinterests me further).