Wheels

[dokotela]

Has anyone ever tried a different wheel size on front and rear axle? For example a 17 in front and 18 at the rear like most supercars. Any significant advantage or disadvantage?

[Vetruck]

I was debating it before I purchase the wheels I have. (I ended up with 18x8.5 fronts/ 18x9.5 rears)

Reason i opted not to is because I run staggared diameters on my Vetruck (18x9.5 fronts/ 19x11rears) and have had a nightmare trying to fit rubber under there all in the same brand and style tire. When I first did this years ago I would run Yoko Advan Sports in a 285/50-18 front and a 295/45-19 rear tire. Eight companies made that sizing at the time I made that choice. 3 years later I had to go to a 255/55-18 front and the same 295/45 rear....then last year event he rear was discontinued and I opted for Pirelli Rosso's because the best I could get was the now same front 255/55-18 and a smaller rear 285-45-19.

If I did not change sizes, I would have to go with Pirelli Scorpion front and a Continental UHP rear which are both crap and would not match either.

[Vetruck]

in my case I was afriad to run into this nightmare again possibly on a second car a few years from now if tire companies start discontinuing staggared choices again. It is much easier to find width staggers in one brand then it is to find diameter staggers.

The advantage to a smaller wheel/larger tire up front is because the front tire is generally skinnier than the rear, SO the taller sidewall makes it more forgiving and thus more predictable in performance driving....as well as a little more comfort. The lower profile YET wider rears will absorb the road better becasue in fact they are wider, so you can reduce the tire sidewall and increase the diameter. So vbasically if the tire is low profile, you need to increase the width to maintain predictability of handling as well as impact comfort. The width gives more surface area to distribute the load when you hit a bump. Otherwise, a skinnier tire will need to be a little taller so the sidewall does some of this absorbing.

My Mercedes right now has a 215/40-18 front / 245/35-18 rear. I was really kindof looking to go a 225/45-17 front and a 255/35-18 rear. I may still do that because I do not like the dartyness of low profile fronts

[dokotela]

Thx a lot vetruck. So overall more advantages than disadvantages. As long tyre brands and series are available of course. Also i came across a set of forged magnesium wheels in 5x112 that I'm seriously considering buying for one of my 202's. Feather weights really so it seems like a no brainer. Only info not available currently is offsets. I'm waiting for the guy to inform me on the back spacing now. But either way I think I'll buy them even though they are not staggered. I'll just space out the rears.

[Vetruck]

Yes pretty much there is an advantage to having a little more forgiveness of a front (or steering) tire. The car will track a little better without being yanked around on road groves as you drive straight. It will track better under hard braking and help keep the car wfrom walking about on the race track width on its own with unwanted steer (again catching road grooves/imperfections, and lastly it will have better volume (the air chamber area just above the contact surface) to absorb road bumps without harsh and abrupt distrotion- hence the dartyness and unpredictable in sudden traction loss in cornering.

Now note the relation of the front tire chamber (just above the contact patch) in a single stagger setup (meaning the widths are staggered- but the wheel diameters are not). The fronts on these will not absorb the road equally to the wider rear tires with more contact volume of patch AND sidewall area.
1662

Now compare that with the next one below that is double stagger (meaning the fronts are narrower AND smaller diamter wheels compared to the wider rear- 17x8 fronts, and 18x9 rears). Also note that going to this diameter stagger you can increase width slightly to get the height in proper proportion to the rear tire height. The first example with both 18's shows you have to go down in front tire width to match the rear height. So a single staggered front will not match in ride proportion to the rear unless you go wider, and thus it gets taller also or else it will bulge improperly if you try to go wider on the silge stagger front setup.. Now you can see why the supercars do a stagger alot when the rear wheel used is wider than the front- they are matching the tire "shock load" both front and rear for a balance.
1663


Dean

[Vetruck]

Also remember that most all cars have more weight over the front tires, especially under hard braking.

Alot of these track only supercars like the Pagani Zonda R have a whole lot of rear downforce as whell as a whole lot of hp. They need a larger diameter rear tire AND sidewall for both low speed acceleration (0-60, which is 2.7 seconds by the way) as well as a tire that will hold up to the incredible downforce at 200 mph. they use a smaller front tire that is actually opposite fromt his theory...why?... the car is built with much more force on the rear, it needs a very small aerodynamic slip stream (hence the small front tires) and is not designed for the hard tight low speed cornering like a typicalVette, etc sees. This thing on a track will not see a corner speed under about 50 mph where as a typical Vette may drop to 35 mph on the same corner. There is alot more lateral strain, alot more rear downforce strain, and alot more braking and acceleration strain on the rear tires than the fronts. the fronts reamain small so the body fits over them better.

Now back to a car like ours, the reason my first explination applied so drastically to us is because our cars were NOT designed and enginnered with an altered suspension geometry to suffice a none proportionate tire impact with the weight and aero we present. You have to consider the chassis orignal engineering specs when considering tire choices. It playus an extreme relevant part in overall handling. Look at the ZR1 Vettes and they are about half as relevant in this stagger as what we would need because the car is designed with a suspeions geometry and a chassis bias better suited to reduce this. they still use the smaller fronts for more maaily aero purposes of the body fitment. Its how the body will load the car under dynamic situations with varying speed. This is where wind tunnel data is used- cars corner weights are scaled under aero force.

[RemoLexi]

Depending on the year of your 202, you will flip out your wheel speed sensors.

[Vetruck]

Depending on the year of your 202, you will flip out your wheel speed sensors.

As long as yo are not changing overall tire diameters different front to rear, then no you are not. That is the point of using the same tire diameters front and rear like I show in the picture links.

[dokotela]

Thx dean. That really helps one understand better.
@remo...as long as the overall rolling diameter stays true to Oem, you should be fine.
The wheels in question are enkei algernon intelesse wheels, 17x8 fronts and 18x9 rears

[RemoLexi]

I'm trying to picture how it would look but idk...

[Vetruck]

I agree Remo, I debated it myself and I think I did a post about a year ago asking if anyone had tried this because I was debating myself if it would look good on a w202. The wheel choice I made did not have staggers availiable so I did not have that option in the end anyways. I really wish I did because I do not like the dartyness of the low profile tires I have up front. They do catch every groove when I have camber on them. A little taller sidewall is more forgiving.