I don't believe the non M X5s have the M driving mode, which basically just makes the accelerator more sensitive. They all have "sport" mode transmission which shifts at higher rpms but the "sport" mode in the X5M is tuned completely differently and is VERY aggressive with lightning fast shifts.

and crazy downshifts

X5M
 

I just drove the X5M this morning at the BMW Power Tour and still have a S-E Grin on my face.

There is no comparison. Different engine (it uses the 4.4 block but everything else is unique to the X5M), drivetrain, suspension, electronic controls, etc. This X is sick fast and handles great. Still smiling...if you can....go for it!! :D :D :D :D :D :D :D :thumbup:!!

I think I might be getting mine this week, silverstone/silverstone interior!

Well worth the extra $20k to me. You will come to the same conclusion as soon as you compare them.

I have just changed from an 08 4.8i M Sport to a new X5 M, its like changing from a bus to a sports car.

What do u mean by this?

On the fence now on buying my dad a x5 50i or the x5m.

I have an 08 4.8 now. Eats gas like no tomorrow. Average about 13mpg for city and light highway and high 14's when combined with more highway. It's the stoplights that really kill the mpg. In this car, shifting is horrible. So either the 50 or m would be a vast improvement. Driving in ds mode in the 4.8 is uncomfortable. Feels like it keeps it in the wrong gear.

Well my X5 M is one of the many that has developed an engine fault, this happened when it was 2 weeks old and its been stuck in the dealer for the last 2.5 weeks, its been returned 3 times with the same fault and is now stuck in limp mode.

BMW quality control seems to be out the window, also the X5 M uses the S63 engine which is a variant of the N63 in the 50i, any inherent problems may well apply to the 50i as many of the components are the same.

I used to have a 4.8i, it was a great car but drove nothing like the M, I normally drive in manual mode, never liked D or D/S and don't like it on the M either but I would rather have a 4.8i on the road than an M in the shop. Maybe the 8 speed box on the 50i is what you need, just beware of *possible* engine isssues.

Thanks for the info. I was not aware of the engine issues. Didn't realize that the quality control has been going down. Overall, my 4.8 has been reliable and I just figured that after a few years run quality should be even better.

I test drove the M and the 50i (very gentle test drive). Didn't get a chance to rev the car very high. Lots of traffic on the road. Wasn't exactly sure what mode I was in for the M. Both cars are fast and responsive off the line (much more than my 4.8). So as far as power. Both are more than adequate. It did feel that if I pushed the M it would have been faster than the 50i.

Reasons to get the M:
Overall the experience inside the M was better too. Nicer leather, specially designed "M mode" HUD display (you can switch between this and regular), nicer looking instrument cluster and love the carbon leather. The looks are better than the 50i w/ or w/o the MSport package. Definitely like the wheels on the M better too and the exclusive glossy roof rails (the ones for the MSport package are silver and doesn't go as well with a Black Sapphire as the black ones do) and soft close doors. On top of all that the performance on the M (acceleration and handling) is superior. Plus my dad's never had a M (though he probably couldn't tell the difference between the 50i and the M).

Reasons to get the 50i.
But paying $15K more for these things seems a little pricey. Then factoring in neither a 50i nor a M will be driven to it's potential (my dad is probably just gonna run errands around town and occassionally take a 40 miles freeway trip to see the grand kids at top speed of 80 miles per hour). Plus the difference in mpg between the 50i and M. It almost seems more practical to get the 50i instead.

So to M or not to M.

Just to balance the equation....My M has had zero problems (well...the ipod cord was a little weak and once the passenger side mirror would not move) and certainly no engine difficulties. It has been more trouble free than the previous Mercedes and Jaguar. I would not let an isolated engine issue be the decider.