I'm pretty sure they're mostly off the rear wheels for everything -- I corrected mine when I installed FRPP Power Pack 1 - and checked against GPS with cruise set -- it's dead on -- was off from the factory -- like Ford cranks everything out with it set to the revs-per-mile assuming every car has 18/235/50 tires. I'm pretty sure speed is measured using an output shaft sensor.285/35 is a standard fit on 10" wheels and look/drive killer. 275/40 is also a great choice. A +40 would be a little tight but should fit. A 5mm spacer is nice (get the ones sized to our hubs) to get some safety margin and push the front wheels out alightly for looks. I run a 5mm spacer with +35 wheels, but I have less clearance to the strut from camber mods. A stock car would be ok with +40, but I'd get the spacer.
I have not noticed the speedo being off by much, and havent corrected it. Reading 64 or 66.0 at 65 mph doesnt bother me . Someone said the speedo might be off the rear wheels anyway?
Yeah I'm pretty dead set on keeping my 19" diameter. I don't mind 20s overall but if rather have some more sidewall. As far as alignments and what not, I'm more inclined for street driving and maybe a visit to the strip once in a while. Nothing crazy since this is my daily.Everything is more expensive with 20's. Ride harshness increases, little higher chance for curb rash, weight goes up. Personally, I don't care for the HotWheels appearance of 20's.
If you get summer tires, I recommend square setup for neutral balance and to rotate and get more tire life. A couple brands even double the wear warranty only when the setup is square.
Aggressive alignments (track day) can work fine on the street but summer tire wear is more susceptible.
Thanks for all the info. For those wondering I was looking into the SVE GT350 reps, since they come in 19" diameter. Their 19X10 size is the +40 offset I'm referring to. If anyone has put the 19X10 S350 in the front, feel free to chime in, not too worried about the rear fitment since I'm not going with a huge 3XX tire. Seems like they intended for the 19X10 to be a front fitting wheel and the 19X11 to be for the rear.
My other choice would be to get the AM GT500 mesh reps, 19X9.5 front and 19X10 rear which seems like a good option and definitely a really good price. They don't list the offset on their site and have the standard text "fits rear only" for the 19X10 size.
Can you post a pic of your set up? I am in the same boat as you were and I am pretty set on going with 19x9.5 +35 on 285/35, square.Same situation here...black accent 19x8.5 on 255/40.
After a lot of pouring over numbers and searching for deals, ended up on 19x9.5 +35 on 285/35, square.
The 19x9.5 or 10 range can fit a number of relatively inexpensive and good performing summer tires, namely 275/40 and 285/35. Go below that and it's not worth the buck for minimal upgrade, and above that, tires get quite pricier and rarer. This is about the sweet spot in price/availability vs performance.
Damn, I wish they would do a deal similar to that on the S350's.https://lmr.com/item/WTK-I1007FD/2015-mustang-sve-drift-wheel-tire-kit-flat-black-19x95-invo
Almost impossible to bet this deal.