Home Forums Articles How To's FAQ Register
Go Back   Xoutpost.com > BMW SAV Forums > X5 (E70) Forum
Fluid Motor Union
User Name
Password
Member List Premier Membership Search Today's Posts Mark Forums Read

Xoutpost server transfer and maintenance is occurring....
Xoutpost is currently undergoing a planned server migration.... stay tuned for new developments.... sincerely, the management


Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 04-02-2008, 11:57 PM
Member
 
Join Date: Apr 2008
Location: San Jose, CA
Posts: 80
davahad is on a distinguished road
Gas vs. Diesel Engine Life

I'm waiting for the X5 Diesel due out later this year and have heard that Diesel engines last much longer than gas engines. Curious what owner's experiences are in this regards and what to expect? Also, is it less expensive to maintain a diesel engine?

Any other pros and cons woud be appreciated.

Thanks.
Reply With Quote

Sponsored Links

  #2  
Old 04-03-2008, 12:22 AM
JCL's Avatar
JCL JCL is offline
Premier Member
 
Join Date: Mar 2005
Location: Vancouver, Canada
Posts: 11,853
JCL will become famous soon enoughJCL will become famous soon enough
There isn't any public high-mileage experience with the most recent BMW diesels since they are fairly recent introductions. Assuming that there are no problems with the aluminum blocks, they should have good life, similar to previous generations of BMW diesels.

Older-technology heavy-duty diesels that routinely went for hundreds of thousands of miles bear little resemblance to today's electronic/aluminum block diesels.

In general, diesels have higher compression ratios, resulting in higher peak cylinder pressures, which are a factor in faster wear. That can be overcome with a heavier block casting, but we are not seeing heavy blocks in modern automotive diesels. Diesels benefit from lower piston speeds, which is a factor in lower wear, due to their lower relative speeds compared to gasoline engines. Both these factors are theoretical to a certain extent.

In practice, considering the complexity of the rest of the vehicle, the car is likely to become very expensive to maintain long before the cylinders wear out, exactly the same as with a gasoline engine.

Maintenance cost? High pressure direct injection fuel systems are very similar these days for gasoline and diesel. Diesels have no ignition system, but how much do we really spend on spark plugs these days? Diesels will be less tolerant of water in the fuel, or of cold weather, and will likely require urea to be added during services, but all in, maintenance costs are likely to be pretty much a wash.
__________________
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
Reply With Quote
  #3  
Old 04-03-2008, 12:24 AM
deutsch100's Avatar
Member
 
Join Date: Mar 2008
Location: Woodland Hills, CA
Posts: 883
deutsch100 is on a distinguished road
I've had 2 diesel cars, a 1983 Mercedes 300TD and a 1992 300D 2.5Turbo. The 300TD had 190,000+ miles, and the 300D has 90,000 miles. Diesel engines are much more expensive to manufacture, but cost much less to maintain. From a German standpoint, EVERY taxi is Diesel, due to the much higher mpg, and most German diesel engines go hundreds of thousands of miles.

There are A LOT Mercedes and BMW passenger cars with 350,000+ miles on the original engine (but more Mercedes )
Reply With Quote
  #4  
Old 04-03-2008, 02:13 AM
Quicksilver's Avatar
Premier Member and retired relic
 
Join Date: Mar 2005
Location: NORCAL
Posts: 17,160
Quicksilver will become famous soon enough
Let BMW speak for themselves......http://www.bmw.com.au/scripts/main.asp?PageID=21935

The latest BMW technology in 6-cylinder diesel engines

The latest 6-cylinder diesel engine from BMW recently made its Australian debut in the 530d and the X3 3.0d. This engine has the latest technology from BMW in the form of an aluminium crank case (previously cast iron) which offers weight savings of around 25kg. It also embraces cast iron cylinder liners which are used to ensure strength and durability. The overall weight saving contributes to improved handling with reduced weight over the front axle, an improved weight distribution over both axles and greater fuel efficiency through carrying less weight.
__________________
"What you hear in a great jazz band is the sound of democracy. “The jazz band works best when participation is shaped by intelligent communication.”
Harmony happens whenever different parts get to form a whole by means of congruity, concord, symetry, consistency, conformity, correspondence, agreement, accord, unity, consonance…….
Reply With Quote
  #5  
Old 04-03-2008, 05:10 AM
Member
 
Join Date: Oct 2007
Location: Belfast
Posts: 559
jimsaq is on a distinguished road
3.0d has been available here for a few years, I haven't been following them closely but haven't heard any horror stories about longevity

time will tell for the 3.0sd which has only been here since about december
Reply With Quote
  #6  
Old 04-03-2008, 07:25 AM
Wagner's Avatar
..make it happn' capn'
 
Join Date: Mar 2005
Location: Mt. Airy, MD
Posts: 17,747
Wagner is on a distinguished road
Quote:
Originally Posted by JCL
There isn't any public high-mileage experience with the most recent BMW diesels since they are fairly recent introductions. Assuming that there are no problems with the aluminum blocks, they should have good life, similar to previous generations of BMW diesels.

Older-technology heavy-duty diesels that routinely went for hundreds of thousands of miles bear little resemblance to today's electronic/aluminum block diesels.

In general, diesels have higher compression ratios, resulting in higher peak cylinder pressures, which are a factor in faster wear. That can be overcome with a heavier block casting, but we are not seeing heavy blocks in modern automotive diesels. Diesels benefit from lower piston speeds, which is a factor in lower wear, due to their lower relative speeds compared to gasoline engines. Both these factors are theoretical to a certain extent.

In practice, considering the complexity of the rest of the vehicle, the car is likely to become very expensive to maintain long before the cylinders wear out, exactly the same as with a gasoline engine.

Maintenance cost? High pressure direct injection fuel systems are very similar these days for gasoline and diesel. Diesels have no ignition system, but how much do we really spend on spark plugs these days? Diesels will be less tolerant of water in the fuel, or of cold weather, and will likely require urea to be added during services, but all in, maintenance costs are likely to be pretty much a wash.
Fully agree

Actual motor to motor, with no car involved, in a bench test...the diesel should almost always out last the gasoline variant. But in the real world, with so many other tangibles....it becomes the idea of better mileage and more torque vs a NA gasoline engine.
__________________

An unwavering defender of those I see worth protecting.

"promote the general welfare, not provide the general welfare"

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.

Reply With Quote
  #7  
Old 04-04-2008, 05:10 PM
Member
 
Join Date: Aug 2007
Location: Undercover
Posts: 236
chonko is on a distinguished road
Quote:
Originally Posted by davahad
I'm waiting for the X5 Diesel due out later this year and have heard that Diesel engines last much longer than gas engines. Curious what owner's experiences are in this regards and what to expect? Also, is it less expensive to maintain a diesel engine?

Any other pros and cons woud be appreciated.

Thanks.
I can't say I have owned any BMW diesel product because that will not be accurate, however this is what I know from Diesel engines:

1. The engines last longer than petrol engines because of the low running speed when compared to their petrol counterpart.
2. Diesels are more viscous than pertol and then to provide extra lubrication to the piston chamber thus prolonging the life of the engine.
3. Diesel engines do not require spark plugs and they are easy to maintain as well.
Reply With Quote
  #8  
Old 04-04-2008, 05:15 PM
Member
 
Join Date: Apr 2008
Location: San Jose, CA
Posts: 80
davahad is on a distinguished road
Thanks for all of the replies and all of the good information.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On





All times are GMT -4. The time now is 02:14 PM.
vBulletin, Copyright 2019, Jelsoft Enterprises Ltd. SEO by vBSEO 3.6.0
© 2017 Xoutpost.com. All rights reserved. Xoutpost.com is a private enthusiast site not associated with BMW AG.
The BMW name, marks, M stripe logo, and Roundel logo as well as X3, X5 and X6 designations used in the pages of this Web Site are the property of BMW AG.
This web site is not sponsored or affiliated in any way with BMW AG or any of its subsidiaries.