Narrover tire size for 21“

[Wolwerine]

Was thinking that the biggest hit to effiency comes from tire widith when you go from 20 to 21 inch. Has anybody put 245/40 and 285/35 vs the standart 265/35 305/30. I would think grip is not an issue with narrower tires and efficiency would be better. Me and the wife are getting a 4s soon and aftermarket wheels are must, i know many disagree.

Sponsored

 

[hifi239]

You could do that, but I don't believe you would find tires meeting the NF0 Porsche Taycan electric spec. In which case you might be in for more resistance and more wear, even if they are narrower. Go with 20" wheels and factory-recommended NF0 tires, is my advice. Also the factory 21"s are indeed really wide, but range isn't clobbered that badly.

 

[Wolwerine]

What I have read, biggest impact to range comes when you go from 20 to 21, not so much when going from 19 to 20. 21 seem to impact range the most radically. Maybe not everyone feels that way. Good point about the nf0, maybe someone just have to try and see what happens

 

[Jonathan S.]

What I have read, biggest impact to range comes when you go from 20 to 21, not so much when going from 19 to 20. 21 seem to impact range the most radically. Maybe not everyone feels that way. Good point about the nf0, maybe someone just have to try and see what happens

That matches up with this nifty calculator:

https://www.porsche.com/international/aboutporsche/e-performance/models/

... and also the lack of any apparent differences in self-reported GOM values from 19 vs 20.

But definitely goes against everything written elsewhere on how EV range in general suffers from both bigger wheel diameters and bigger tire widths, which is ... confusing.

As for going with a 21" wheel but downsizing the tire width from OEM and increasing the tire profile from OEM so as to preserve the OEM tire diameter, the only major benefit would seem to be lots of fun calculations at https://tiresize.com/wheel-offset-calculator/!

 

[Wolwerine]

Well, narrowing the tires gives almost exactly the same dimension than standart 20" so I would think the effiency stays almost at same level.

 

[Jonathan S.]

^ True, if the goal is to gain the handling and/or appearance benefits from a shorter sidewall, while minimizing (or perhaps even eliminating entirely) the range drawbacks from a larger diameter wheel, then that could work out well.
(As for the parenthetical aside, I've read articles that just a shorter sidewall from a bigger wheel hurts range, and some marques report lower EPA ratings for that ... both others do not -- confusing!)

 

[Wolwerine]

Like I said, I think maybe I just have to try and see, luckily the tires are so cheap at 21"

 

[cityhpper]

What I have read, biggest impact to range comes when you go from 20 to 21, not so much when going from 19 to 20. 21 seem to impact range the most radically. Maybe not everyone feels that way. Good point about the nf0, maybe someone just have to try and see what happens

I drove about 10 000 kms on the factory stock 19", my observations when changing to 20" was a range penalty hit of about 3-5 percent. Not very noticable unless you really need to strech it between chargers.

I suspect there is some correlation between this and the somewhat larger contact patch of the 20" tires, the increased aerodynamic drag of the wider tires and the aerodynamic properties of the wheel designs. But hard to say, since there are many factors at play.

 

[mjw930]

Check those sizes against the recommended wheel widths. On the 20’s the bead is already stretched, it’s really noticeable on the rears to the point it opted to bump up to the 21’s with my new wheels. I really dislike the look of tires mounted on wheels that are too wide. I’m actually quite disappointed in Porsche that they did that and can’t for the life of me understand why they didn’t speck narrower wheels.

 

[Wolwerine]

The 21" wheel widtht will be the same as 20 inch or even 0.5" narrover, these will be aftermarket wheels.

 

[cityhpper]

Check those sizes against the recommended wheel widths. On the 20’s the bead is already stretched, it’s really noticeable on the rears to the point it opted to bump up to the 21’s with my new wheels. I really dislike the look of tires mounted on wheels that are too wide. I’m actually quite disappointed in Porsche that they did that and can’t for the life of me understand why they didn’t speck narrower wheels.

Also, the Michelin PS4 NF0 tires are quite narrow for their size in 285/40R20. The Pirelli winters (not NF0) I use, have far less strech on the same wheel (rim) width.
For the Turbo S wagon, Porsche also options 255/45 and 295/40 if on the 20"s. Should give a more beefy apperance.

Sponsored