[W288SH]

I posted what happened to my first 25 X5 40i here a few weeks ago. Car was totaled and I had a new X5 on order the same day.

My prior 25 had 21” 915s and the latest one has 22” 742s.

I feel like this one isn’t as quick. I was impressed with how quick and responsive the 25 with 21s was.

[PunsGalore]

I mean they weigh more, but is it that much more that you notice a difference in acceleration?? Most likely just in your mind, unless there's something like an alignment issue..

[sharkymcpeterson]

I’ve felt this way before about my
M50. I have a dragy though so anytime I get paranoid I can do a run to confirm.

[BlkGS]

It's in your head, or a result of air temperatures or something like that. The slight weight difference is likely not something you're going to feel in a big SUV like this unless you were really trying to

[matowi]

Should also be mentioned your new ride looks great!

(despite the black wheels, which I don't generally find any good )

[MystroX5]

The ride is smoother with the 21”ers and that may translate in what you are feeling. I run both 21”AS and 22” summers and much prefer the 21”ers in ride and handling. Not a staggered wheel fan on a big SUV. You probably will be o.k in NC with summer tires as long as you avoid temps below 40 and any slush/snow.

[IceLed]

Originally Posted by MystroX5

The ride is smoother with the 21”ers and that may translate in what you are feeling. I run both 21”AS and 22” summers and much prefer the 21”ers in ride and handling. Not a staggered wheel fan on a big SUV. You probably will be o.k in NC as long as you avoid temps below 40.

Is it though? 21" are RFT, 22" comes with a summer set. I tested both and in my personal opinion, because of the RFT the ride quality was the same (both vehicles were with air suspension).

[jad03060]

Back-to-back between a virgin, green engine versus one with some run-in miles, I'd expect the one that is broken in some to perform better.

Then, there will be at least some variation between different examples, but without proper tools to test it, it's likely just a misperception.

[MystroX5]

Originally Posted by IceLed

Is it though? 21" are RFT, 22" comes with a summer set. I tested both and in my personal opinion, because of the RFT the ride quality was the same (both vehicles were with air suspension).

Absolutely. I took two identical 4k mile road-trips from PA to Florida with both sets a year apart. The 21”ers were quieter on every road surface and noticeably smoother. The 22”ers were not bad but the 21 just had more sidewall giving it a bit more isolation. The 21ers 285/45/R21 are a square setup and not as wide as the massive 315/35/R22 22”ers on the rear.
The DHP/air suspension on the X7 really hides a lot and I would bet the difference would be greater without air suspension.

[W288SH]

Originally Posted by jad03060

Back-to-back between a virgin, green engine versus one with some run-in miles, I'd expect the one that is broken in some to perform better.

Then, there will be at least some variation between different examples, but without proper tools to test it, it's likely just a misperception.

They were both virgin engines. My prior X5 was totaled with all of 665 miles on it!

The second 25 feels more like my 23 which had the 335 hp b58 not the 375 hp.

[cfm56d7b]

Originally Posted by MystroX5

The ride is smoother with the 21”ers and that may translate in what you are feeling. I run both 21”AS and 22” summers and much prefer the 21”ers in ride and handling. Not a staggered wheel fan on a big SUV. You probably will be o.k in NC with summer tires as long as you avoid temps below 40 and any slush/snow.

Echoing the same. 21” wheels offer the best balance between performance, comfort, and replacement tires cost.

[matowi]

I must be made of wood, I guess, because I experience no difference in comfort whatsoever. Moreover, in my view, the handling improves with 22” non-rof summer tires as compared to 21” rof winter tires. This is however a minor difference

The largest difference is in noise levels - summer 22”s are definitely quieter, especially when it’s wet

(For the record, I have the m adaptive professional suspension, and I’d describe it as providing the same level of comfort as my previous 7 series with air suspension on 21” summer wheels; but truth be told, it’s not as comfy as an X6 with air suspension and 20” winter tires which I had as a loaner a while ago)

[11010X101]

Mathematically... 21" has about 0.5 inch more rubber. So 22" is about 0.5 inch larger overall. With the same rotational force, 22" is supposed to be "faster" but this may be balanced by the additional weight if that's the case. In any case, the difference is too insignificant for a driver to be able to detect IMO. From my experience, 20" and 21" are day and night when comfort is considered.

[PunsGalore]

I'd take 740M wheels or any 21-inch wheel over a 22-inch wheel set..

[W288SH]

Originally Posted by PunsGalore

I'd take 740M wheels or any 21-inch wheel over a 22-inch wheel set..

I had the 20” on my 23 and the difference in turn in response is noticeable.

This is interesting…I thought the 22” setup would have an overall larger circumference than the 21” but it’s the opposite.

[jad03060]

Originally Posted by matowi

Moreover, in my view, the handling improves with 22” non-rof summer tires as compared to 21” rof winter tires. This is however a minor difference

I don't think any winter tire will handle as well as a summer performance tire, at least around the temperatures they are designed for...

[GREENPUS]

I switch between 20’s and 22’s on the same car. No difference in “quick”

[jad03060]

When you choose OEM sizes, the OD and thus turns/mile remains almost identical across the choices. There should not be any change in gearing. There might be a slight change in grip, depending on the tires selected. Handling is also very dependent on the tire selected. A larger wheel assembly is usually heavier, and may actually have slightly different (less) overall efficiency values, but usually it's not much...more important maybe with an EV. A wider tire will have more drag, and more options of hitting some debris and going flat as it's covering more surface area than a narrower tire.

[rost7]

Low profile tires give more precise steering and better feedback, it is proven by many tests. Also a kind of less comfort but it may not be noticeable on premium cars, good suspension and soundproof compensate it.
Accelerating depends on specific tire model, especially if you drag race using launch control which creates an extreme initial punch which hits the traction limit of the tire and the surface.