effect of wider tires (+ wider wheels) on steering feel and nimbleness

[tm1v2]

Minimizing as many differences as possible - same offset, same wheel diameter, same wheel construction (for similar weight), same tire / tire category - Does going with wider wheels+tires hurt steering feel or that sense of nimbleness in tight back-and-forth turns / twisties? For example, 245 vs 265 or even 275, each on appropriately sized wheels of the same diameter, and same offset (or minimal change if needed for inner tire clearance).

I've put different width wheels and tires on my cars before, but always with too many variable changes to attribute everything to width, e.g. summer vs winter tires, or lightweight forged wheels vs heavy Uberturbines.


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Here's my situation. With the stock M3P 235/35R20 Pirelli PZ4 on 20x9" Uberturbines I found myself wanting more grip. (Street only, no plans to track this car.) I recently changed to 245/45R18 Bridgestone Potenza Sport on 18x8.5" forged Titan7 T-S5. I did it just to get more sidewall and stronger wheels, because I drive on lots of rough roads, unpaved driveways, etc. My plan was for these 18x8.5" to eventually become my winter wheels, and get wider wheels for summer, either 18" or 19" diameter depending how I felt about the 245/45 sidewalls.

Well, turned out this initial wheel+tire change was a much bigger improvement than I expected. Like I said, I was mainly just looking to avoid cracked wheels from bad roads, but I got way more than that. The new tires grip much better, the steering feels better, the car feels more nimble in tight twisties, and of course ride quality is better with the taller sidewalls (just smoothed out a bit, not transformed). All this and the taller sidewalls don't feel mushy at all with these tires, at least not in my street driving.

So now I have a dilemma. I'm actually pretty happy with the grip of these 245 width Potenza Sports, not really feeling the need for more grip anymore. That said...I know the M3P can fit wider for even more grip, without body or suspension mods. (Or lower treadwear tires, but I'm sticking with 300ish treadwear for a street-only car.) Besides the wheels and tires costing a bit more, is there any real downside to going wider, say 265s on 18x9.5" or 275s 18x10" ? I would go with forged wheels again, there's be some weight gain just from the extra wheel+tire width but hopefully not much.

I'm most concerned about preserving the sense of nimbleness in tight back-and-forth turns, and also steering feel (which actually improved slightly too with the new wheel+tire setup). I'm not sure how much I'd actually put the extra grip to much use in the twisties, but I would on roomy empty highway ramps.

Basically my heart says "Go wide and grip to the death you chickensh***!" while my head says "the current setup feels perfect, and it saves money + efficiency to not go wide, just get another set of 18x8.5 for winter and call it a day." I could even be boring and get another set of exactly the same wheels, so I'd effectively have spares from my summer & winter sets being the same wheels (not same tires of course).

Any thoughts?

 

[Mash]

I have 19x9.5 275x35 4s set for the street. It's quite optimal for performance, standard pressure in optimal zone, side grip is good enough. I don't suggest going 10 wide wheels - it's more tricky to fit in front.

 

[SocalM3P]

I was curious about this, too and posted something some time ago but my thread got merged with the general tire questions thread. I'm still contemplating 265 30 20 to replace the 235 35 20 Pzero's when the time comes but do not want to sacrifice the nimbleness of the OEM set up.

 

[tm1v2]

I have 19x9.5 275x35 4s set for the street. It's quite optimal for performance, standard pressure in optimal zone, side grip is good enough. I don't suggest going 10 wide wheels - it's more tricky to fit in front.

I hadn't really thought about wrapping 275s around 9.5" wide wheels but I'm actually liking that idea (if I go wide). Lots more 9.5" than 10" wheel options off the shelf, I guess because of the fitment issues you mentioned. And 275s would help keep the diameter just slightly larger than stock, which I prefer over slightly smaller than stock as I'd get with 265s.

What offsets are you using front and back? (Accounting for spacers of course if using any.) Any need for other adjustments e.g. extra camber to fit the 275s without any rubbing? Note I'll be keeping stock ride height (even with my coilovers).

 

[tm1v2]

I guess this also comes down to how much extra enjoyment I'd actually get from more grip.

If I was doing track days still I'd want all the width / grip I can easily stuff in there, the more the merrier at the track. But I'm not taking my M3P to the track any time soon (or ever most likely). Will my skills and b*lls grow big enough to safely use the extra grip from 275s on twisty back roads with little margin for error?

I'm actually thinking 255/45R18 on 18x9 might be ideal for me on the street, just a tiny bit extra wide. But it's real slim pickings for tires and wheels in that size, so it's not really an option.

 

[Mash]

I hadn't really thought about wrapping 275s around 9.5" wide wheels but I'm actually liking that idea (if I go wide). Lots more 9.5" than 10" wheel options off the shelf, I guess because of the fitment issues you mentioned. And 275s would help keep the diameter just slightly larger than stock, which I prefer over slightly smaller than stock as I'd get with 265s.

What offsets are you using front and back? (Accounting for spacers of course if using any.) Any need for other adjustments e.g. extra camber to fit the 275s without any rubbing? Note I'll be keeping stock ride height (even with my coilovers).

I'm using et30 on sv503 Signature wheels. Since I have aftermarket brakes, they effectively function as ~5mm spacers vs stock m3p brake rotors. That particular setup fits well, except you need to reposition wheel speed sensor cable otherwise it will be destroyed.

It's probably the largest setup that doesn't need camber adjustment. My track wheels are 10.5 et25 with 295x35 r18 a052 and they need 10mm front spacers and more camber.

 

[Mash]

I guess this also comes down to how much extra enjoyment I'd actually get from more grip.

If I was doing track days still I'd want all the width / grip I can easily stuff in there, the more the merrier at the track. But I'm not taking my M3P to the track any time soon (or ever most likely). Will my skills and b*lls grow big enough to safely use the extra grip from 275s on twisty back roads with little margin for error?

I'm actually thinking 255/45R18 on 18x9 might be ideal for me on the street, just a tiny bit extra wide. But it's real slim pickings for tires and wheels in that size, so it's not really an option.

My experience is that more tire width doesn't add side grip, but rather stability of it except in hydroplaning situations.

 

[jackmott]

If you aren't racing competitively don't complicate your life for an extra 1% of grip. Wider tires will cost more, weigh more, worse aero, require you spend a ton on wider wheels, and on and on and on.

Spend that money on something sensible like sex and drugs. I mean education and paying down debt.

 

[Dallas J]

Wider is absolutely better if you're trying to win something. Current tires can take a pretty low tire/weight ratio and still come up to temp. Like Miatas running 275s (and some on 295s). My Evo is about 200lbs lighter per corner up front and on 315s. But if you're just a street car, it doesn't matter really. Something with some grip is good, but I don't push a car hard on the street so its sorta irrelevant.

More or Better tires will give more grip, but it will also give greater fall off on backroads when you hit water, gravel, oil, or whatever that starts some slip.

As for steering feel, what tesla has that?

 

[gearchruncher]

Current tires can take a pretty low tire/weight ratio and still come up to temp. Like Miatas running 275s (and some on 295s). My Evo is about 200lbs lighter per corner up front and on 315s. But if you're just a street car, it doesn't matter really. Something with some grip is good, but I don't push a car hard on the street so its sorta irrelevant.

Agree with all you said, but just to reinforce that for any good street tire, getting up to temp isn't really relevant. One of the things that makes a great high performance modern street tire with high wear ratings (like a MPS4S) really great is that the grip is available from 40F to 120F+.

The exact tire you go with will have way more to do with how the car feels and grips than the difference between 245/265/275 section widths on the street.

 

[tm1v2]

Thanks all! This was helpful. I will stick with my current wheel & tire sizing, I think it makes the most sense for me.

Now the only dilemma left is whether to just get a second set of identical Titan7 wheels, or have fun with something different. Any suggestions for other 18x8.5" forged wheels that fit the M3P hubs and don't break the bank? I want stock ET34 offset, and I prefer no spacers, but might be okay with 3mm or 5mm spacers if needed so long as the resulting offset is correct.

(I feel like I'll probably end up with a 2nd set of Titan7's. I have seen the Jova wheels thread btw, but I don't want to go that route.)

Spend that money on something sensible like sex and drugs. I mean education and paying down debt.

I didn't go to college so no education debt. Sex and drugs it is then, thanks!

As for steering feel, what tesla has that?

Lol, yes I know what you mean. Teslas are just typical for modern cars though. I can list on one hand the cars I've driven with truly good steering feel. Most had manual steering. But I get a bit of information through my M3P's wheel and I don't want to lose what little it has.

 

[gearchruncher]

Any suggestions for other 18x8.5" forged wheels that fit the M3P hubs and don't break the bank?

The way to not break the bank is to get rotary forged wheels. The weight savings of forged wheels is not making any difference except to the weight of your wallet. There are tons of options on the market that fit fine given the same fitment as Mustangs if you are willing to run a hubcentric ring and they fit the step just fine.

 

[tm1v2]

Tbh I like forged for strength, way more than I care about the weight savings.

I'm still scarred from cracked Tesla wheels, and I do more driving on rough roads than ever these days. Flow formed doesn't help with spoke strength and that is the weakest part in my experience.

 

[Dallas J]

Forgestar wheels are pretty popular these days. I have F14s in 18x12 for the Evo (The real race wheels are Volk ZE40 though) and CT5V in 19x9 on the Tesla.

 

[dfwatt]

I was curious about this, too and posted something some time ago but my thread got merged with the general tire questions thread. I'm still contemplating 265 30 20 to replace the 235 35 20 Pzero's when the time comes but do not want to sacrifice the nimbleness of the OEM set up.

What people are describing here in terms of 'nimbleness' seems a little bit vague but I can assure you that when you go from the stock 235/35 to, for example, Michelin Pilot Sport 4S 265/30s on the front you do not lose transient response. Or ultimate grip. Just the other way around. My transient response seems much better with wider tires although this is likely multifactorial including possibly due to the shorter side wall as much as anything else. I have to confess I've also done numerous other things including MPP coilovers (the sport version) set a bit firm, forged wheels that are between 6 and 7 lb lighter a corner than the stock ones despite being much wider, and I've swapped out the lower front control arm bushing which makes a huge difference in steering feel. All these things are probably improving transient response in combination. Front lower control arm bushing also probably improves turn in because the stock bushings flex quite a bit on high lateral loads probably affecting steering geometry undesirably. At least that's what MPP has reported and I trust them.

 

[jackmott]

This is pretty simple calculus:
If you want to go faster around race tracks or autocross courses or corners: Wider tires will do that
If you do not want to go faster, the factory size will have much better range, be cheaper, be lighter, etc.

As for feel, people imagine feel stuff, one tire model to another might change feel more than a little width. Someone who goes from Brand A 235 to Brand B 265 might think feel got better/worse because of width but really it was because of brand B. It isn't really a thing worth worrying about. Either you want to go faster so fit as much tire as you can, or you don't, so don't bother.

 

[Motion122]

Wider the better! 265 on 9.5" will easily fit with et30-35. 275 on 9.5-10" will need careful selection of offset and some added camber. Some tires run much wider than others so take that into consideration as well. Do not deviate too much from the factory offset of add too thick of spacer trying to correct offset or create clearance. The change in geometry with different offsets or spacers can have a negative affect on the handling of your vehicle.

 

[Motion122]

Forgestar wheels are pretty popular these days. I have F14s in 18x12 for the Evo (The real race wheels are Volk ZE40 though) and CT5V in 19x9 on the Tesla.View attachment 751639

I like!

 

[Atraf]

@tm1v2 you might like this post:
https://teslamotorsclub.com/tmc/posts/6283461/

If I was doing the above now days I would have gone with the "Plus" variant of the DWS06 tires.
Also super wishing that FastWheels EV01(+1) came in same 18x9 et+30mm variant that the FC04 do.
And would totally be happy to pay 2x to have it forged instead of flow formed.
Already losing range on width, no reason to also lose range on aero.... but doesn't look like FastWheels (or anyone else, ex "The New Aero") are into that idea.

 

[SkylerH]

I guess this also comes down to how much extra enjoyment I'd actually get from more grip.

If I was doing track days still I'd want all the width / grip I can easily stuff in there, the more the merrier at the track. But I'm not taking my M3P to the track any time soon (or ever most likely). Will my skills and b*lls grow big enough to safely use the extra grip from 275s on twisty back roads with little margin for error?

I'm actually thinking 255/45R18 on 18x9 might be ideal for me on the street, just a tiny bit extra wide. But it's real slim pickings for tires and wheels in that size, so it's not really an option.

I don’t know about 255/45R18. But there are some really good options for 255/40r19. Namely there’s an awesome summer pz4 customized for the bmw i4, that has more eco low rolling resistance compound in center when at constant speed but still has good acceleration and breaking and a stickier compound on the shoulfer for turning. I really really wanted this tire but didn’t realize until after I bought 19x9.5 wheels. You would want 19x9 wheels for those. If I could do it again I would get the 9” wide wheels.