Because existing sources of auto reliability information left much to be desired, in late 2005 I started conducting my own reliability research at TrueDelta.com. TrueDelta reports absolute stats like "trips to the shop" that make the differences between cars much clearer. Results are updated four times a year, so any significant changes in a model's reliability become apparent quickly.

So far one or more years of the C, E, and GL are included in the survey. I'd like to also include the M--just need additional owners to sign up to participate first.

Participants simply report repairs the month after they occur on a one-page survey. When there are no repairs, they simply report an approximate odometer reading four times a year, at the end of each quarter.

To encourage participation, panel members receive full access to the results for free.

For the details, and to sign up to help out:

Vehicle reliability research

 

Now 76 for all model years. Better, but more remain needed.

Vehicle reliability research

 

Add me to the list. Ibought a 2004 ML500 almost two months ago and so far I love it and no problems.

Ken

 

Thanks, I appreciate it. I can't add you myself, but you can read the details and sign up here:

Car reliability research

 

184 M-Class owners now signed up. The 2000, 2006, and 2007 are now in the survey, and other years also getting close.

To help us provide stats on your year:

Car reliability research

 

Just enhanced the related repair history survey so that it can (optionally) be used as a personal car maintenance record.

As always, more participants would be helpful. Updated Car Reliability Survey results in May, with a preview for participants next month.

Car reliability research

 

Updated results in about two weeks.

It looks like one model year of the M-Class will just barely make it in, while two others will fall just a little short of the minimum sample size.

We will have another update in August. Help get your year included:

Car reliability research

 

We have an initial reliability stat for the 2007 M-Class based on owner experiences through March 31, 2010. With a reported repair frequency of 152 repair trips per 100 cars per year, it's worse than average. The sample size is small, so this result might not be accurate.

Thank you to everyone who has been helping. We'll have further updates in August and November. With more participants, we could provide more precise information and cover all model years.

 

We've updated results for the M-Class to include owner experiences through June 30, 2010.

Other sources of car reliability information won't cover the more recent months until the summer or even fall of next year.

Repair frequencies, in terms of repair trips per 100 cars per year:

2007: 125, worse than average

2006: 98, about average

Very small sample sizes in both cases, so these results are not precise.

Thank you to everyone who has been helping. We'll have further updates in November and February. With more participants, we could provide more precise information and cover all model years.

To see how competitors compare, and to sign up to help:

Mercedes-Benz M-Class reliability comparisons

 

My 2001 ML55 126000, had the following items replaced over the 6 years of ownership. Are you ready? Brakes 2x, motor mounts, CO sensor, Brake Hose x2, steering pump, Steering rack, keys, brake booster, brake switch. Door remote still doesn't work, Steering wheel was cracked by stealership in madison wi, they refuse to replace. I know for a fact it all worked when i brought it in for service. I estimate about $800 bucks every 6 months to keep it on the road. I have updated the front grill, tires, and all the lamps to newer plastics, and body clear coated.