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 While the actual innovation/functionality of the given technology will be quickly outdated it will function as designed provided there are not glitches for a very long time.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.

[JCL]

Originally Posted by 140.6

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.

IMO (Mech Eng with IT and power generation controls/measurement experience) there will be a spike of occurences early on, then fewer issues throughout the vehicle's life. That is due to the nature of electronic component failures.

However, purely as an example, for two similar vehicles both at 100,000 miles, one with more options and one with fewer options, you are more likely to have problems with the one with more components. They don't go to zero failures as they age, they just go to fewer than when new. Less complex always beats more complex, in my experience. Things that are age-related include harnesses, sensors, corrosion, heat damage, and so on.

Said another way, if I had ongoing problems from new, that vehicle would not be a candidate to keep long term as I wouldn't see it getting better. But if I had no significant problems from new, I would still expect the less complex vehicle to be more reliable on average.

If you do decide to go with what one might term 'old school option selection' ie limiting option choices in the interest of long term reliability, then the diesel may be a better choice simply because the V8 may have more standard options that you can not delete. That comes down to package consist, not engine reliabilty. One reason I liked the 3.0 gasoline models was that I got to build up the options that I felt I really needed, and I didn't get unnecessarily complex options bundled in the standard build. In my case, I managed to avoid Nav, HUD, back-up and side-view cameras, telephone integration, lane departure warning, active seats, active suspension, etc.

[5wany]

Originally Posted by JCL

... limiting option choices in the interest of long term reliability.....

each to their own, but I thought one of the many reasons to buying a new vehicle was because it had all the latest technology.

To not add stuff as it might break, to me is just plain daft. You get ur warranty period, if it last that long its likely to keep on going. If there is a fault that develops after say 5+ years its pretty likely other owners will have succumed too, so a fix will likely be available.

TBH I would not worry too much, its a new car been in production for 4 years now so many of the bugs have been fixed.

Go on get the 5.0i you know u want to

[Richard in NC]

Originally Posted by JCL

One reason I liked the 3.0 gasoline models was that I got to build up the options that I felt I really needed, and I didn't get unnecessarily complex options bundled in the standard build. In my case, I managed to avoid Nav, HUD, back-up and side-view cameras, telephone integration, lane departure warning, active seats, active suspension, etc.

An interesting discussion with no real way to know the answer unless we had the full picture of maintenance records, etc of cars with age on them. The 4.4TT just isn't that old to know its longevity.

Regarding limiting options. That is a strategy for avoiding problems but it also prevents having and enjoying said options for the life of the vehicle. I've got most of those options and enjoy them all.

[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.

[JCL]

Originally Posted by 5wany

Each to their own, but I thought one of the many reasons to buy a new vehicle was because it had all the latest technology.

To me, that is a reason to buy a new television or cell phone. Someone (I think it was Tony Hogg at R&T several decades ago) once defined sports cars as ones that didn't have anything on them that didn't make them go faster. I think cars are better without too much technology. You can focus on driving, instead of watching video screens. But to each their own

[nd200]

Personally, I would go for the V8. BMW has to add extra hardware to make this vehicle a clean diesel. Take a look at the technology used (not rocket science but not simple either). If you plan on keeping the car a few years past the warranty period, you could be in for some expensive repairs when these additional components begin to fail.

[dbox]

TT V8

[Quicksilver]

Seriously:
Your saying "A far better comparision to an automotive diesel would be the Oldsmobile V8, with the diesel that was made out of a gasoline engine. That didn't work out so well. Or consider the Smart diesel." Are you comparing BMW diesels to Oldsmobile V8 diesels? If so (I'm no expert) but I find that hard to believe...

Originally Posted by JCL

It is really difficult to compare large displacement (11-15 litre) medium duty diesels to 3 litre automotive diesels. Wet cylinder liners, heavy cast blocks, and so on, vs aluminum blocks, just for a start. Fuel system complexity is significantly different, at least until medium duty diesels have to meet the same emissions standards. The old automotive diesels that ran forever (Mercedes, Peugeot, etc) were low speed, heavy, low tech diesels. They have almost nothing in common with modern automotive diesels. A far better comparision to an automotive diesel would be the Oldsmobile V8, with the diesel that was made out of a gasoline engine. That didn't work out so well. Or consider the Smart diesel. I don't think that will just be getting broken in at 80,000 miles.

I think a 3 litre BMW diesel will last just fine, but it will wear out a little bit sooner than the similar 3 litre gasoline version due to the higher peak cylinder pressures, and a little bit later due to the lower revs. Probably a wash overall. Both the diesel and gasoline versions will last longer than the rest of the vehicle, however.