Forget MPG ... Best Long Term Option 50i or 35d

[JCL]

Originally Posted by 140.6

Completely understand where you are coming from, however I respectfully disagree. While the actual innovation/functionality of the given technology will be quickly outdated it will function as designed provided there are not glitches for a very long time.

Having said that if there are computer related issues my bet is, I could be wrong here and if I am so be it, that reprogramming the car is much cheaper than replacing an engine. Now that assumes a catastrophic failure in the engine but that is what we are talking about here in terms of long term reliability.

I agree that the functionality will generally continue operating as designed and built, but I think that history has shown that there are glitches. And the glitches that matter aren't just in the technology (ie Nav, back up sensors, cameras, HUD, etc) but in the integration of the various technologies. That is what has parked vehicles over the past few years. Look at the example of battery charging. Pretty simple concept, you have a storage battery, various devices run off it, and the alternator charges it. Voltage drops to a certain point, and the regulator causes the alternator to charge the battery. This has worked for 80 or so years. But BMW has put all of their computerized modules on a common data bus. They have a sleep mode. If a single module does not enter sleep mode, the vehicle stays 'awake' and you have a flat battery after several days of parking. It is one or more of the various computer modules that cause that. And the more modules you add to the mix, the greater the odds. The E70 has an 'energy management system' that takes a book to describe. And it is that system that has caused factory buybacks, brand dissatisfaction, etc, to the point that dealers started giving out battery tenders and advising owners to plug them in at night. For both gasoline and diesel models.

[140.6]

Originally Posted by JCL

I agree that the functionality will generally continue operating as designed and built, but I think that history has shown that there are glitches. And the glitches that matter aren't just in the technology (ie Nav, back up sensors, cameras, HUD, etc) but in the integration of the various technologies. That is what has parked vehicles over the past few years. Look at the example of battery charging. Pretty simple concept, you have a storage battery, various devices run off it, and the alternator charges it. Voltage drops to a certain point, and the regulator causes the alternator to charge the battery. This has worked for 80 or so years. But BMW has put all of their computerized modules on a common data bus. They have a sleep mode. If a single module does not enter sleep mode, the vehicle stays 'awake' and you have a flat battery after several days of parking. It is one or more of the various computer modules that cause that. And the more modules you add to the mix, the greater the odds. The E70 has an 'energy management system' that takes a book to describe. And it is that system that has caused factory buybacks, brand dissatisfaction, etc, to the point that dealers started giving out battery tenders and advising owners to plug them in at night. For both gasoline and diesel models.

Fair enough. The question that remains is that if you have a "trouble free" vehicle throughout the warranty period are you really more likely to have it develop electronic gremlins later in its life. I am not an EE and cannot answer that with any confidence.

[o-steve]

If I were buying one long term I would extend my lease and wait for the new model to come out in 1-1/2 years. Decide then!

[rh71]

V8 revs = bigger smiles than the low RPM diesel revs in my opinion. Long-term, anyone's guess, but I'd still go V8 if given the 2.

[dbox]

TT V8

[4MoJoe]

I had the 'old' 3.0i, 4.4i and now the diesel. My 3.0 gave me less headaches than my well cared for 4.4i did but the V8 gave me more smiles. However, at the end of the day the constant repair issues of my 7 year old 4.4i broke the deal. I couldn't depend on it (and I may have been one of the few that is just kept nailing me to the wall on repairs).

I bought my x35d with significantly less options than I had wanted but really it's quite adequate for me; a V8 was not on my list because of past experience. But I think you'll have fun with either vehicle.

[David Mc]

V8's are fun, but everything that is expected to work and last is diesel - large trucks, tractors, trains, heavy equipment. The reason is simple, assuming proper routine maintenance (i.e. regular oil/filter changes and clean fuel), the answer to engine longevity comes down to getting the highest possible engine torque at the lowest possible rpm, using the least amount of moving (and therefore potentially wearing) parts. If BMW had released the X5 with their V10 engine and I were to vote for the V10 in preference to the V8, it would be purely on the basis of fun to drive factor. Sorry guys, but based on reasoned logic, my vote has to be for the diesel.

[BGM]

Here is the data supporting (or not supporting) long-term durability of those 2 motors:

1) 35d: None
2) 50i: None

What we do know:
1) Non-aspirated I6: BMW's bread and butter and is bullet-proof
2) Non-aspirated V8: Not as reliable as I6

[JCL]

Originally Posted by BGM

Here is the data supporting (or not supporting) long-term durability of those 2 motors:

1) 35d: None
2) 50i: None

What we do know:
1) Non-aspirated I6: BMW's bread and butter and is bullet-proof
2) Non-aspirated V8: Not as reliable as I6

Agree with your conclusion, but let's call them naturally aspirated, as compared to forced induction.

[140.6]

Originally Posted by BGM

Here is the data supporting (or not supporting) long-term durability of those 2 motors:

1) 35d: None
2) 50i: None

What we do know:
1) Non-aspirated I6: BMW's bread and butter and is bullet-proof
2) Non-aspirated V8: Not as reliable as I6

Not sure I completely agree with the "None" for the 35d. My understanding is that the M57 engine in various incarnations has been around for awhile. I will grant you that it has not been around nearly as long as various iterations of the I-6. At then end of the day I think Ard had it right early in that BMW has the numbers that would support a more accurate conclusion but the public is not likely to ever see those numbers.

So it looks like I will be making my decision based on "smiles per gallon." In which case I think we can all see where this is headed, I'd place the odds at 3:1 for the 50i at the moment and trending higher.