I don't think turbo reliability (or unreliability) should be a factor in your decision at all.

I think the reports that state the LCI X5 with both turbo 35 and 50 gasoline engines will be out in the spring really mean May deliveries, and I wouldn't recommend that you race to have one of the first ones.

If you were interested in the diesel, it would be worth waiting for the LCI X5 40d which reports are floating around on. This engine was released for the 740d, and is listed at 306hp, with improved torque as well. Reports are that it will be available in the X5. I don't know if that means the X5 35d will be discontinued, or whether both can exist, ie a performance version of the diesel.

There will always be another improved model just around the corner. If the one you like is here at your dealer now, drive it and enjoy it. These probably aren't vehicles that you want to own for 10 years in any case.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue