MRGTX

Am I the only one who finds this frustrating?

255s in a summer-only compound are decent for stock tires but any Mustang owner worth their salt would obviously want more tire on the road, especially when we have to shell out a good chunk of cash ($1000+) when it's time to replace them.

Stock BBP wheels- 19x9, stock tires are 255/40/19 = 27.031" tall.

Common wisdom says that if handling is important, the widest tire that should go on a 9" wide wheel is a 275...and there are a couple of good high performance tires choices in that size, but you have a diameter issue-

275/35/19 = 26.579" tall (almost 1/2 inch shorter)
275/40/19 = 27.661" tall (more than 1/2 inch taller)

Some folks will say that it doesn't matter..but if you're at stock ride height, the shorter tires are going to increase the already ugly wheel gap and give you a slightly shorter contact patch, the taller tires will increase the overall ride height and give you a numerically lower final drive ratio which can hurt accelleration. Either will slightly alter the accuracy of the speedometer. No thanks.

Yes, these differences are small and many/most folks are happy with 275/40/19s...and that's ok but there's an even BETTER size that's just so close:

285/35/19 = 26.854" tall (less than .2" from stock!)...and noticably wider. This size also provides the option of the popular (and cool looking) Bridgestone Potenza RE-11 which is by most accounts comparable to the Michellin Pilot Super Sports and will put over $100 back in your pocket compared to the Pilots.

Unfortunately, these are slightly too big for stock BBP wheels... yes, SOME folks are running 285s on the 9" BBP wheels but they'e likely experiencing some extra sidewall flex and loss of contact patch under hard cornering. Ideally, these would be riding on 19x10 wheels...or 9.5s would probably be fine too.

So what do you do? I guess most just buy the 275/40s, pay more for the Michellin Pilot Super Sports and forget about the extra diameter.

2010GBGT

I'm actually waiting for the tire store to open this morning so I can get my tires mounted and balanced. I bought the Boss LS wheels and going with 255/40 in the front and 275/40 in the rear. Picked up a set of Cooper Zeon A/S from Discount Tire so we'll see how it goes. I know everyone recommends summer and winter sets but I always had A/S on my 94 GT vert. Never had an issue the 13 years I drove it daily. Obviously wasn't driving through 6"-8" of snow so the A/S got me through a few inches leaving work.

MRGTX

Keep us posted on how you like them!

The Boss/LS wheels are 19x9.5, right? Did you consider 285s? If so, why did you pick smaller ones?

2010GBGT

Will do!

I wanted to go with the Coopers and they didn't offer a 285. The LS's are 19x9 & 19x10. From the specs, they run a little wider so I should be ok. One wheel done, waiting on the other 3...

5.M0NSTER

I've been struggling with the same dilemma. I track my car, and I'm looking for a set of wheels/tires for track days. The largest selection is in 285/35-19 category, with pretty good selection in 275/40-19 as well. I'm planning on buying the AM GT500 wheels in 19x9.5 to accommodate the wider tires. Most tires with widths between 265 and 285 are measured on 9.5 wheels.

I'd prefer to have a larger overall diameter tire. Here is my reasoning. My track Pack came with 3.73s which are a BLAST on the street, but I find them a bit short for the track. I redline mid corner and have to shift just past the apex every so often, while I'm still turning. So a taller tire will give me a ~2 or so more MPH in each gear. Also as you mentioned a larger overall contact patch. That's the reason I'm leaning towards 275/40-19. I used one of the gear ratio calculators and it looks like sticking 275/40-19 is equivalent to having 255s with 3.64 gear ratio. I think that will work for me.

Another thing to consider is for some reason the tires I'm leaning towards (Bridgestone Potenza S04 Pole Position) are actually cheaper in 285 than they are in 275...

So I feel your pain.

wheelman

They do have 285s for the summers, if you weren't already aware, but yeah, not for the A/Ss.

MRGTX

Yep...you nailed it. It sounds like you have this pretty well figured out. At least you have a solution.

As someone with 3.55 ratio (and who is happy with that) I really don't like the idea of dropping them to essentially 3.4x:1

Which AM GT500 style wheels did you opt for?

As for the tires being cheaper in 285, I have noticed that too...that's purely a fuction of demand/production numbers, I imagine.

bryan67

you do realize you dont have to stay on the 19 rim platform. with the 3:55 gear(same as i got) definitly going 285 rear and then 255 up front. when i need to get my next set of tires. Got DOT drags for the rear dropped to 16 in rim. and looking to go 17 front runners for at the strip up front.

laserred38

You going to pay for the OP's new wheels?

MRGTX

I have gotten to the point where the 19s look correct to my eye...even if I had the cash for new wheels, I'd stay with 19s. Actually, I'd likely go 2010GBGT's route with the Boss LS/19x10 wheels but that's just not in the cards right now.

Having a second set (or pair) of tires for the drag strip would be fun...maybe some day...

2010GBGT

Yeah, I saw that but couldn't justify having two sets at the moment. I work from home when it snows and by the time I go in the next day, the roads are usually clean. It's my daily driver and I'm not pushing it to the limits like some on the track etc.

TheDivaDanielle

i'd go with the taller tires, as the BBP cars have the SHORTEST tire diameter of all the Mustangs (and therefore the most wheel gap)

2010GBGT

Here are some pics. At work now so this is the best I could do. Suspension going on when the weather warms up, asap. Feakin 4x4...lol

wheelman

I can justify it for my DD all day, but it still doesn't mean I have the cash, lol, so I bought the same tires and size as you.

5.M0NSTER

I think you're right. 285 is more popular.

In terms of wheels I'm pretty set on these:
http://www.americanmuscle.com/charco...9x95-0513.html

I love the style, I like the Charcoal finish (better for hiding brake dust) and it's not too expensive. I'd rather not scratch the $250 Brembo wheels.

figit

MRGTX this is exactly why I got super frustrated and decided to relegate my 19x9 TP wheels to winter duty. It just didn't make sense for me to spend that much on half a$$ tires when I wanted better. I sold the stock pirellis on craigslist for $300 and picked up some thin blizzaks for the stock wheels for just under $600. So for $300 total I had a set of dedicated winter wheels & tires.

I know you didn't mention being in the market for some wheels but if your looking at nearly 1k for a decent set for the 19x9s it might be worth considering getting a package deal for wheels and tires somewhere for under $1,500 with 285s on the rear. AM has staggered setups like that for under $1,500 but the wheels themselves weigh a ton. I ordered a square setup of SSR GTV-01 19x9.5 wheels (24lbs.) from Jay & Dan at hypermotive.

I'm waiting on those now. I'm going with 285/35s all the way around so I can rotate them easily after track events. The initial outlay was more than I anticipated spending but I just couldn't stomach sacrificing on tires while still having to throw 800 to 1k at the stock wheels. I noticed your in CT so the above route would yield you what your going for while still having a set of dedicated winter wheels/tires.

laserred38

I can't wait to see that setup!

5.M0NSTER

O.P. I think Mike has a good point. So how do you feel about 285/35-19s on some nice and light wheels? Technically you your gear ratio would increase a bit, and you get more grip for harder launches. Other than a $700 wheel buy in it might be an awesome package in the end

But if buying wheels is out of the question, I guess 275/40-19 is the best way to go.

Thomas S

I went with the Continental DWS 275/40 all around. I wanted to stay with the Brembo wheels and since I have 3.73s the slight height difference didn't hurt much. According to my GPS my speedo is only reading about 1-2mph low. Very happy with my choice. These tires hook much better than stock and have a treadwear rating of 540.

Ltngdrvr

If you are going to replace the wheels as well as the tires for track duty, you could always go with 18" wheels, opens up the door to a lot of possibilities. And you aren't going to lose any cornering abilities with the right combo, and will probably drop some weight.