Mercedes-Benz GL450 reliability - how does it compare?
The thing is, both are rare. Only about one problem in 20 requires a tow, and only about one in eight renders the car undriveable. And this is for cars of all ages--they're even more rare for fairly new cars. Which people probably don't realize, so this would be good information to get out there.
The more rare something is, the larger the sample size you need to accurately measure it. Even to do the latter I'd like to have a minimum sample size of 250. We're simply not there yet.
People who buy brands known for reliability do tend to be more interested in reliability surveys. But the major factor is how many of a model are sold. In the first seven months of this year Mercedes sold 10,596 of the GL, while Acura sold 24,724 of the MDX.
I'm trying to decide if I should buy an extended warranty right now and part of my diliemma is that I have to ask myself if saving the few thousand dollars by not replacing my GL every 4 years is worth the potential interruption to our family vacation from a car breakdown. Honestly, saving a few thousand dollars by keeping my GL two additional years isn't worth being stranded in Western Michigan for a day while my GL gets worked on.
Some rough calculations with conservative assumptions...
You're on vacation for perhaps two weeks a year, and perhaps 15% of the total miles driven for the year? The odds of a problem that must be fixed right away at any point in the year are perhaps one in four for an out-of-warranty GL. So the odds of a breakdown on vacation might be one in 25 each year.
Spend even $1,000 to avoid that one in 25 breakdown, and you're essentially paying $25,000 per on-vacation breakdown.
Now, I haven't factored in Murphy's law...
I don't know, it's really difficult to weigh all the factors and come up with a single answer. And clearly it's not an easy thing to do because, well, nobody has done it. Like I've said before, at some point you're getting that "smile factor" from your German diesel!
Remember, I count any repair as a repair. Many GL's have needed to have their door handles replaced. You probably don't have to interrupt a trip for a broken door handle.
I don't know the specifics behind the air suspension failures. Does the system fail in a way that the car can still be driven?
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As always, the more owners participate, the better the information we can provide to everyone.
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Also this month: updated reliability stats.
Repair frequencies, in terms of repair trips per 100 cars per year:
2008: 80, about average, and a substantial improvement from earlier; sample size right at the minimum
2007: 163, worse than average
Thank you, once again, to everyone who has been helping. We'll have further updates in February and May. 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 GL-Class reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2008: 89, about average
2007: 128, worse than average
Thank you, once again, 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.
To see how competitors compare, and to sign up to help improve this information:
Mercedes-Benz GL-Class reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2008: 134, worse than average
2007: 125, worse than average
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 improve this information:
Mercedes-Benz GL-Class reliability ratings and comparisons
minor nuisance issues handled by warranty? 1 on the 2007. Quality issues? None. Expectations for this vehicle? Met them all. Faith in the vehicle? 100%! Miles: 2007 had 70,000 the 2011 has 8000.




Repair frequencies, in terms of repair trips per 100 cars per year:
2008: 173, worse than average
2007: 112, worse than average
Thank you, once again, everyone who has been helping. We'll have further updates later this month and in May. 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 improve this information:
Mercedes-Benz GL-Class reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2008: 118, worse than average -- common problems with air suspension and steering rack
2007: 131, worse than average -- common problems with air suspension and power liftgate
Small sample sizes in both cases.
We'll have further updates in February and May. We'd love to provide more precise stats and cover more model years--just a matter of getting more owners involved!
To see how competitors compare, and to sign up to help improve this information:
Mercedes-Benz GL-Class reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2008: 143, high
2007: 99, high
Small sample sizes in both cases, which could explain the difference between the stats. Also the 2008s are still under warranty.
Thank you, once again, everyone who has been helping. We'll have further updates in May and August. The more owners participate, the more comprehensive and precise these will be.
To see how competitors compare, and to sign up to help improve this information:
Mercedes-Benz GL-Class reliability ratings and comparisons
1. Small sample sizes
2. People might have taken the 2008s in just before the factory warranty ended, while they might be letting things go unrepaired with out-of-warranty 2007s.
With more participants we'd have more precise information.
The data published is the number of failures (or trouble) REPORTED in the various categories. If it doesn't get reported we don't know about it [and we cannot assume failure]. There are a couple of reasons for not reporting:
1) The owner didn't know [or care] that there is a mechanism failures COULD be reported. This likely true for the owner that lets the dealer 'handle everything'.
1.2) It was fixed and not reported
2) It wasn't fixed - and therefore not reported [like MKaresh said: out-of-warranty might equal no fix.
3) Owner didn't know it was broke! eg "I didn't know that light on the dash meant anything" There ARE folks like that!




The data published is the number of failures (or trouble) REPORTED in the various categories. If it doesn't get reported we don't know about it [and we cannot assume failure]. There are a couple of reasons for not reporting:
1) The owner didn't know [or care] that there is a mechanism failures COULD be reported. This likely true for the owner that lets the dealer 'handle everything'.
1.2) It was fixed and not reported
2) It wasn't fixed - and therefore not reported [like MKaresh said: out-of-warranty might equal no fix.
3) Owner didn't know it was broke! eg "I didn't know that light on the dash meant anything" There ARE folks like that!
1.2 This is possible but it would not skew the results to the extent we are seeing with the 2008. I'm thinking the differences are a result of the assembly line's standards slowly relaxing after the initial production push or suppliers relaxing quality control after the first batch because they were not put under the microscope as much as the first batch of cars. A much smaller sample size could also change the results but it could have swung the total opposite way if the owners had more problems.
2. Is highly unlikely. Typically items that brake on the GL have to be fixed or the car is not driveable. Transmission valve plate and air struts come to mind as the most common repairs on the GL's followed by a slew of problems with the 320/350 not seen on the 450.
3. See comment above. Things that affect the GL also affect the driveability of the car. You can't help but notice.
We've updated our reliability stats for the GL-Class to include owner experiences through March 31, 2013.
Repair frequencies, in terms of repair trips per 100 cars per year:
2008 GL-Class: 135, high, small sample size
2007 GL-Class: 105, high, small sample size
We'll have further updates in August and in November.
For the details, including the descriptions of reported repairs, and to sign up to help improve this information:
Mercedes-Benz GL-Class reliability ratings and comparisons
Last edited by mkaresh; Jul 31, 2013 at 01:15 PM.
Repair frequencies, in terms of repair trips per 100 cars per year:
2008 GL-Class: 103, high, small sample size
2007 GL-Class: 130, high, small sample size
We'll have further updates in November and February.
To view competitors' scores and descriptions of reported repairs, and to sign up to help:
Mercedes-Benz GL-Class reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2008 GL-Class: 129, high, small sample size
2007 GL-Class: 122, high, small sample size
We'll have further updates in February and in May. The more owners participate, the more comprehensive and precise these will be.
To see how competitors compare, and to sign up to help improve this information:
Mercedes-Benz GL-Class reliability ratings and comparisons


