Oops it only references the 20s. I'll do some more digging. If an X5M does like .98-g with Adaptive and an 35i Adaptive with only 19s does .87-g, I would think it's safe to assume Adaptive with 20s falls in between both (definitely not less).

These numbers would make sense given that the 20s wear wider rubber, meaning a larger contact patch with the pavement (thereby a higher friction coefficient between the vehicle and the pavement) which will result in better stopping and skid pad performance if everything else is essentially equal.

Also, on a 5000lb vehicle, the effect of the heavier 20s is less than on a lighter vehicle in these types of tests.

An update on my X5:

My X5 seems to have become lost in repair hell. The shop told me that they had several of their mechanics come down with the flu and were running over a week behind. Ugh. Hope to have it back next week, which will be 3 weeks in the shop.

All is not lost, though:

I had a very gracious friend loan me her 2016 C450 AMG Mercedes while she is out of town on business. It's a pretty sweet ride. It would really be a tough call between the C450 (or C43) and a 340i. The Merc definitely steers and handles better than my recent experience with a 435i, and the interior on the Merc is also a step up in my opinion.

The 340i is not a 335 or 435. There were numerous differences that addressed the steering feel (or lack thereof). My 340i with MPPSK is definitely a match for the C43

Which is exactly the point I was trying to make. They are quite comparable.

more to come
 

I just finished valve seals, valley pan, coolant pipe, and water pump on my '07 4.8. I currently have 105K on the truck, but the valve seals starting smoking probably around 75K, so I would factor in a valve seal job into your calcs. I did mine myself, so cost me $560 ($500 for the AGA tool kit, and $60 for the seals), but I've read that indy's are charging around $2500-$3K for valve seal jobs. Also, I've also done gaskets for timing covers, valve covers, alternator, so I think I have all major issues addressed...fingers crossed! If I had to do it over again, I would have bought something else, although the X5 is a wonderful ride when it's not broken.

I've done much of the same work in the last couple of month and if I had to do it over again, I would have bought this vehicle differently (informed negotiating :D ), but still would have went for it.

But... I enjoy the DIY and the payoff.

Pushrod, sorry to hear about your 4.8i wow's.

But this is exactly why I dumped my 2008 X5 4.8i and replaced it with a 2011 X5M with an extended warranty. I managed to spend over 8K in parts/maintenance in 6 months on my 4.8i. I did almost all the work myself and it seemed like every weekend I was working on that car. I will say so far the X5M has been significantly more reliable, and less expensive to maintain. In fact even though my 4.8i was paid for, I was averaging 1300/month in repairs. I have a spreadsheet that tracks costs, but damn, everything broke, sunroof, alternator, pcv, diff seals, suspension, e-brake, thermostat, heater control valve, MAF, etc. My X5M with an extended warranty costs my $435 in payments. It was money saving for me.

Oh my 2008 X5M 4.8i with 96K miles and 0 issues other than bad valve stem seals (which weren't noticeable with ATP-205). I traded mine in march 2017 for 9500. It was a fully loaded X5 4.8i with adaptive drive, multi contour heated and cooled seats, etc. I like the newer X5M but there is an M tax, and oh my goodness are brake pads and tires expensive.

Time to Cut Bait? (E70 4.8i Issues)
 

Same thing here. Dumped the needy N62 and stayed with the economical X5M. I have paid my N62 dues but will never renew again. Had 3 of them (4.4i, 4.8is and 4.8i). Every one a bit of a disaster in their own way.


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I'm confused--you are leaving some information out. How many miles did you have on your '08 4.8? You're only paying $435/month on an '11 X5M--how many miles and what kind of warranty? Even with $9K trade, on a 60 month finance you paid $35K-- you did a 5 year note on a 6 year old car?