285/30 R21 on staggered 9.0" Turbines?

[Fjols]

I have an 85D with the OEM staggered Turbines. So 245/35 front and 265/35 rear. Runs great, but I'd like a wider stance in the rear.

I know 285 is not recommended for a 9.0" rim, but wondering if anyone has done it? I don't care about range or cornering dynamics TBH. I just want a wider tire in the rear. Preferably on stock Turbines and no spacers.

My main concerns are 1) whether they would rub if I put the suspension in low and 2) if the tire wall would bulge out too much and ruin the aesthetics.

Pictures would be much appreciated if anyone is running 285/30 on a 9.0" Turbine.

 

[Sunshine State]

We have been running 275/35’s for years, they work great with lots of tire options. The 285/30 is 2 percent smaller diameter than stock and also has an 8 percent thinner sidewall for more potential damage. Teslas seem to forgive the slightly taller 275/35 over the stock 265/35 but keep in mind the all wheel drive ratio is altered and having smaller diameter rears doesn’t seem to be worth the disadvantages.

 

[Fjols]

Thanks for the insight. I actually much prefer 285/30s because the diameter/sidewall/RevsPerMile matches that of the front 245/35s 99.5%, contrary to the 265/35s.

Glad it's working out for you, but I already think the sidewall is a little too tall on the 265/35s (compared to the 245/35s), so 275/35 is out of the question. Don't need the extra protection. Been running Turbines for almost 5 years (Square during winter and Staggered during summer) and never had any damage.

No one running 285/30 on 9.0" Turbines or Arachnids for that matter?

 

[Sunshine State]

Thanks for the insight. I actually much prefer 285/30s because the diameter/sidewall/RevsPerMile matches that of the front 245/35s 99.5%, contrary to the 265/35s.

Glad it's working out for you, but I already think the sidewall is a little too tall on the 265/35s (compared to the 245/35s), so 275/35 is out of the question. Don't need the extra protection. Been running Turbines for almost 5 years (Square during winter and Staggered during summer) and never had any damage.

No one running 285/30 on 9.0" Turbines or Arachnids for that matter?

It may match the sidewall height of the front tires but that isn’t exactly the point. The car is set up when running on 21’s to have taller rear tires unless you tell it you are running 19’s then it would likely be fine to have matching front and rear tire diameters. The Tesla system seems very forgiving unlike the stability systems in other cars. If you started mix matching tire diameters in a Porsche it would have big issues with it.

 

[Fjols]

It may match the sidewall height of the front tires but that isn’t exactly the point. The car is set up when running on 21’s to have taller rear tires unless you tell it you are running 19’s then it would likely be fine to have matching front and rear tire diameters. The Tesla system seems very forgiving unlike the stability systems in other cars. If you started mix matching tire diameters in a Porsche it would have big issues with it.

Not quite. The cars are not set up specifically for staggered wheels (not including the old + suspensions). It simply is not needed. This is also the reason why Model S throughout the years have been delivered with and without staggered wheels. Like the 2015 P85Ds. Even in the exact same configuration (non + suspension) some came with staggered and some with squared wheels, depending on which 21s Tesla had in stock.

My car came from the factory with squared 21s. When I change to staggered 21s there is no other difference than stance and slightly worse range (and slightly better/neutral grip through corners at high speeds due to more rear rubber).

After the wheel configurator was introduced with 2019.32.1 all it really does is adjust estimated range and potentially the air suspension depending on size of wheel you choose. It does not adjust traction/stability systems. It does not need to.

Yes traditional ICE car setups may complain when your revs/rpm are out of wack. Especially AWD. But this is not comparable with Teslas because they're inherently adaptable due to electronically controlled open differential, independent axles/drive units.

With 275/35 the sidewalls are too tall and the rear will be a little too elevated for my liking. I am picky like that. Most wouldn't notice.

In any case, I am strictly interested in putting on 285/30s for the aesthetics.

 

[Sunshine State]

Sorry I couldn’t help. I have different taste and don’t like the smaller sidewall look in the rear so we never put 285/30’s on. I’m really fussy about my cars aesthetics and I agree that most people wouldn’t notice the difference but I do. I’m a tire fanatic and have dozens of Tesla Turbines, Arachnids and Twin Turbines in silver, grey and carbon fiber wrapped. I once put non staggered width tires on one of our Performance S’s once because we wanted to carry a single spare tire on a long road trip but I didn’t like the smaller appearance with less sidewall in the rear and replaced them. The 245/35R21’s in the rear just seemed to look too small with the thin sidewalls in the S rear wheel arches. If you prefer the smaller non staggered 21" look I guess the 285/30 profile is a good option. It’s just not for me. I admit I’m not sure about Tesla adjusting the stability management system based on tire size but do know the tire we run seem within acceptable values so the non staggered 21" size would seem to be fine too. An extra 5mm on the inside seems like it would fit. Tesla service techs can’t give a straight answer on the stability management but say it does measure wheel speed differential but I’ve never got information from a Tesla software developer to know for sure what is too much.

 

[ddawson]

I have 20x10 on the rear with a 295 tire. The wheel offset is +40.

You can do the math and see if it will work on the stock 21 offset.

 

[ddawson]

Ok so I ran the calculator.

10" +40 vs 9" +40
Inner clearance = 13mm more.
Outer Position = RETRACT by 13mm

The centerline doesn't change so it's just the extra 1/2" on each side so width wise it will fit.

 

[Fjols]

Nice rear view. The sidewall looks rather tall, are those 295/35-20?

Upon further inspection, 285/30-21 should definitely work on stock rear turbines. However, as the stock 265s are already quite close to the inner wheel lining I may have to do some slight molding to be on the safe side.

 

[ddawson]

Correct 295/23-20 Slightly small diameter then OEM at 28.1"

 

[SurfHappy2]

Fjols, I know this post was from two years ago. Have you tried the 285/30-r21 and do you have any issues? I’m thinking the same for my P85+ with 21” OEM Turbine wheels. Let me know what tires you bought and your experience. Thanks!