Tires and Performance on the street

[ElectricGhost]

Not the most scientific method, but I was researching some things and came across Car and Driver specs on the model 3's with different tire options. This gives you and idea of the change from 235 Primacy MXM4 all-season's to 235 Michelin Pilot Sport 4S.

I attribute deltas 100% to tire compound as the brakes are not hot enough for caliper size to matter and I'm assuming maximal brake torque/wheel lock inducing ABS was applied during testing. I'm also assuming lower profile doesn't make these numbers better although feel may improve.

My conclusion is narrow tire with sticker compound is the best option for daily. I am assuming lower road noise, better efficiency, and improved braking. Looks like its time to order the 245/40/19's over the 265/35/19's I was considering.


MXM4's
"The car we tested rode on the base 18-inch tires, which means workaday 235/45R-18 Michelin Primacy MXM4 all-season rubber. As such, the chassis test numbers—a 176-foot stop from 70 mph and 0.84 g around the skidpad—were unremarkable, even by mainstream-family-sedan standards"
- Braking, 70-0 mph: 176 ft
- Roadholding, 300-ft-dia skidpad: 0.84 g
2018 Tesla Model 3 Long Range Instrumented Test

PS4s
"The Model 3 stopped from 70 mph in 147 feet where all the gas-burning competitors needed at least 150. The Tesla produces strong deceleration from the regenerative system as soon as the driver lifts off the accelerator, even before applying the left pedal to bring the friction brakes into play. Also credit the grippy performance tires and upgraded brakes—the regular rear-drive Model 3 with the standard brakes and shod with all-season tires on 18-inch wheels produced only 0.84 g of lateral grip and needed 176 feet to stop from 70 mph."
- Braking, 70–0 mph: 147 ft
- Roadholding, 300-ft-dia skidpad: 0.95 g
2018 Tesla Model 3 Performance Rules the Passing Lane

And for an idea of "wide tires = better" theory
"Expectations of greater lateral grip from the wider-than-stock Michelin Pilot Super Sport tires (265/30 front, 285/30 rear) and stiffened suspension similarly went unmet. The Competition-package car recorded 0.99 g on our skidpad—0.01 g less than the best figure we’ve gotten from a regular M4 and only 0.05 g better than the worst figure we have on file from the lineup, that being from an M4 convertible."
2016 BMW M4 Coupe DCT Competition Package – Review – Car and Driver

 

[MasterC17]

I completely agree. I've been trying to convey this for months. Your experience with the tires is much more dependent on the compound than the width. What people need to decide when selecting new tires is, what is most important to me?

If you value efficiency, an Eco-Focused tire is your best option (Primacy MXM4)

if you value performance, a Summer tire is your best option (PS4S)

If you value winter performance, a Winter tire is your best option (X-Ice XI3)

If you want a tire that is OK at everything, an all-season is your best option (PS A/S 4)

Simply put, no tire is going to do everything well, tires are a compromise.

Doing something like putting All-Season's on and then increasing the width by 30mm "because performance" is really silly. Not to mention, 95% of people will never reach the limit of their tires on the street.

 

[Mash]

The reason for wider tires is primarily heat capacity and dissipation. 235 on 20 were instantly dead for me on the track and 275 on 19 were keeping up reasonably well. Don't go wider tires for street - it doesn't make sense.

 

[XLR82XS]

The reason for wider tires is primarily heat capacity and dissipation. 235 on 20 were instantly dead for me on the track and 275 on 19 were keeping up reasonably well. Don't go wider tires for street - it doesn't make sense.

The only reason I'm going to 245 from 235 is for increased wheel protection. Aftermarket 19x8.5 wheels are in the pipeline.

 

[Zextraterrestrial]

I completely agree. I've been trying to convey this for months. Your experience with the tires is much more dependent on the compound than the width. What people need to decide when selecting new tires is, what is most important to me?..... 95% of people will never reach the limit of their tires on the street.

I'm a 5% daily driver since I got my P85 almost 8 years ago
lots of compound 'testing'

 

[Dolemite]

A 265/35 19" square setup will provide more ultimate grip than a 245/40. Whether or not that difference is worth it to you on a DD is... up to you.

As of now I'm DDing 265/35s during the warmer months. Will probably get some OEM-sized A/S 4s for cold weather/range driving when I blow through the hateful MXM4s. But that occasional moment of open road where you can really wring it out is worth it to me. The grip is just astronomical and massively entertaining... first time I've heard my wife bypass anger and go straight to laughter. I may try 245s next just for kicks - the narrowest size that'll properly fit on a 9.5" rim.

 

[Olavxxx]

A 265/35 19" square setup will provide more ultimate grip than a 245/40. Whether or not that difference is worth it to you on a DD is... up to you.

As of now I'm DDing 265/35s during the warmer months. Will probably get some OEM-sized A/S 4s for cold weather/range driving when I blow through the hateful MXM4s. But that occasional moment of open road where you can really wring it out is worth it to me. The grip is just astronomical and massively entertaining... first time I've heard my wife bypass anger and go straight to laughter. I may try 245s next just for kicks - the narrowest size that'll properly fit on a 9.5" rim.

Yes, but it of course depends on for what usage.
If just doing drag race straight ahead (1/8 mile), the OEM PS4 tires in 235 width have enough traction for the 3P.
I have tried different tires/wheels and it seems the best way to increase accelleration is lighter wheels and same width.

But of course on auto-x or a track with a lot of curves/braking, one can overheat the tires and then either wider tires or PILOT SPORT CUP 2 R would be good. But I think the 4S is the best tire if one wants to both go on track and drive on street, because at least in my country we have a lot of rain and the 2 R would then be easier to aqua plan with as it has less water drainage channels. This part of the tire without water drainage is of cours ealso what makes it better for heavy track usage (at least in dry conditions), but it could maybe be dangerous in my country on public roads if driving in large puddles. The 4S on the other hand is SUPERB at wet roads for daily driving also.

 

[lbowroom]

If you look at tire tread width details, one version of the Michelin 4S 265 20” is 8.9” while the TO version 235 is 8.8”. Section width is significantly wider on the 265.

I mention this because for the street one can get better fender fill (section width and height) without really increasing rolling resistance.