[rotortalk]

I had assumed that the conventional wisdom was the bigger the wheels, the lower the range - presumably it is not the actual wheel size per-se but the wider tyres on the bigger wheels giving more air resistance (&/or rolling resistance??)

So the standard 21" on the 50 was fine for me.

However, from the US press released posted by @ecobimmer, I quote

... indicating an EPA range of up to 324 miles with 20-inch wheels, 305-miles with 21-inch wheels and 315 miles with 22-inch wheels.

What? Hold on, the 22's are more efficient than the 21's? Is a £1,000/£1,350 upgrade worth 10 miles? Or even a free (?) downgrade to 20's for 19 more miles! 19, that is more than most PHEVs can do on e-only!

 

[Evrim]

I have seen these figures as well, I suppose it is based from BMW USA website.

On all EU based and UK sites if BMW, it is always mentioned as larger size of wheel, lesser range. Theoretically, 22 inch wheel cannot have more range than 21 inch.

For example, below text is from BMW UK site:

The selection of larger alloy wheel and tyre sizes generally reduces the range (if the aerodynamic disadvantage is not compensated for by a more closed wheel design). The rolling resistance class of tyres is also relevant for the range: e.g. the use of a winter tyre reduces the range compared to a Label A summer tyre.

Additionally, US and EU range ratings are very much different as they use different norms. WLTP versus EPA. As far as I know this is based on road properties and usage statistics.

 

[Laix]

I'm really interested in this.

I have a regular 300 mile journey that is hoped could be charger free.
On the 21s I got about 260 miles at motorway speed + the tolerated margin in the UK😉.

Clearly at 3-5C range will be impacted, and a bit slower may help.

Seeing the range data really annoyed the m sport trim moved me to the worst range.

 

[ExiPaceOwner]

On the 21s I got about 260 miles at motorway speed + the tolerated margin in the UK😉.

I've just come from an Ipace, based on my experience of that (ie miles per kwh), I was hoping for 250(ish) at motorway speeds. I did a 512 mile round trip last week, (80 miles on A roads), and ended up with 2.6 miles/kwH . ie about 260.

I was VERY happy with this, after the ipace (which of course has a smaller battery). Plus the speed of charging seems to be a lot faster (at a fast charger).

 

[ICS_UK]

I have a regular 300 mile journey that is hoped could be charger free.
On the 21s I got about 260 miles at motorway speed + the tolerated margin in the UK😉.

Your 260 miles is that total or charger to charger I'm hoping to see charger to charger range of 200 ish in my MS 50
charger to charger being 80% to 10%. I got that (estimated) on a run with cruiise set at 78 (ground speed 75) I have 22's