Inside Line spent 12 months with one of the least successful Mercedes-Benz products in recent memory. Our long-term review of the 2006 Mercedes-Benz R500 is complete following more than 25,000 miles on the road.

Why We Bought It
Mercedes introduced the R-Class as an all-new vehicle for the 2006 model year. Buyers seeking a sedanlike driving experience with SUV-style interior space and minivan-style convenience were expected to comprise the target market. Demographically speaking, affluence was a requirement for these people, dictated by the R500's $55,500 MSRP.

We walked away from our first drive of the R-Class confused with the purpose of this vehicle, and questioned its marketing. If we wanted a minivan, we wouldn't spend the money on a Mercedes. And if we were in the market for a Mercedes, we wouldn't settle on a minivan.

An extended period of time with the R-Class, we hoped, would help us understand the niche this vehicle filled in the marketplace. With a long-term 2007 Cadillac SRX already in the pipeline for our test fleet, the addition of the Mercedes offered us a unique point of comparison between these two luxury crossovers.

We chose the R500 over its R-Class siblings for eight cylindrical reasons. The R350's V6 just didn't tickle our fancy quite like the 302 horsepower and 339 pound-feet of torque offered by its big brother's 5.0-liter V8. We likewise passed on the diesel-drinking R320 CDI and the gasoline-gulping R63 AMG.

Durability
The R500 found most of its acclaim as a long-distance cruiser. Chief Road Test Editor Chris Walton drove the Mercedes several hundred miles to visit family in Northern California. He noted in the logbook, "The scale of the R500 makes it susceptible to crosswinds, but otherwise it devours highways and hills with ease. It is largely silent when running at 80 mph, although there's some tire noise on rougher pavement. Driving position is excellent and I could easily go three or four hours behind the wheel thanks to a 300-plus-mile fuel range."

Not everyone found the R-Class so comfortable over the long haul, however. Senior Editor Ed Hellwig wrote, "Without much time in the R500 I was a little suspicious of other editors who whined about its hard seats. Every time I took a short trip, they felt just fine — great, even. This weekend I finally took a nice long trip to Monterey in the Benz, and you know what? The whiners were right. The R-Class chairs start feeling a little stiff after awhile and you're left wishing for something a little more Lexus-like. If it were a sedan I would cut it some slack, but there's nothing sporty about this minivan wannabe."

Over the life of our R500, the rear liftgate gave us some grief. It was not uncommon for the liftgate latch to need multiple attempts before latching securely. News Editor Kelly Toepke noticed it first. On the long-term blog pages she wrote, "Three times this weekend I opened the R500's rear power hatch, and three times it failed to close properly on the first try. Only one time did the rear-hatch-open warning display on the instrument panel. The other two times I realized something was wrong when the interior lights didn't go off, even after I started the car." This issue is well documented by R-Class owners on the CarSpace forums. In our case it was remedied under warranty by replacing the faulty latch mechanism.

Problems with the Mercedes were otherwise limited to minor items. A burned-out parking lamp was replaced during its 26,000-mile service for $10. Rock chips in the windshield were repaired by Dents-Out Plus mobile glass repair for $50. We accidentally washed the key fob in a pair of jeans, and when it failed, we simply used the spare.

The R-Class' massive proportions spelled trouble while maneuvering it around town. Over the 12 months we piloted this behemoth, it tallied three significant altercations with inanimate objects, all of which happened at low speed in parking lots. Collectively these incidents caused damage to the rear quarter panel, wheel, fender and both bumpers. We repaired the blemishes for a total of $1,220.

We used Mercedes-Benz of Long Beach for routine maintenance on the R500. Advisors were not especially helpful during our visits at 13,000 or 26,000 miles, though the appropriate maintenance items were performed to our satisfaction each time. We chose this dealership for its convenient location. Had money or quality of service been determining factors, we'd have taken our business elsewhere.

Total Body Repair Costs: $1,220
Total Routine Maintenance Costs (over 12 months): $498.05
Additional Maintenance Costs: None
Warranty Repairs: Install exhaust shim plates between front exhaust-system brackets and transmission (13K); replace tailgate latch assembly (26K).
Non-Warranty Repairs: Replace burned-out front parking lamp, windshield glass repair.
Scheduled Dealer Visits: 2
Unscheduled Dealer Visits: None
Days Out of Service: 11
Breakdowns Stranding Driver: None

Performance and Fuel Economy
Our V8 R500 lived up to its promise of sport-touring speed. Performance results varied little between its first test at 1,400 miles and its final exam at over 25,000 miles. It needed 6.9 seconds to reach 60 mph from a stop and completed the quarter-mile in 15.1 seconds at 91.8 mph. From 60 mph it came to a stop in 128 feet under full ABS.

Stability control cannot be fully defeated on the R-Class, so the ultimate dynamic performance of this 5,023-pound family hauler is understandably compromised. After the completion of its fastest slalom run at 61.2 mph, Senior Road Test Editor Josh Jacquot commented, "The R-Class feels bizarre in the slalom. With very little body roll control and loads of engine torque, it can be hard to avoid stability control intervention when you dip into the throttle at the end of the slalom. It tends to be very erratic." The R500 pulled 0.77g on the skid pad.

Fuel economy in the R500 varied quite dramatically over our 25,000 miles behind the wheel. We recorded 12 mpg on multiple occasions during city driving, though it wasn't out of the ordinary to see 22 mpg on the highway. We spent most of our time shuttling the Mercedes around town, which explains its 16-mpg average economy.

Best Fuel Economy: 22.3 mpg
Worst Fuel Economy: 11.9 mpg
Average Fuel Economy: 16.4 mpg

Retained Value
According to Edmunds' TMV® calculator, the value of our $62,115 R500 depreciated 23 percent during our 25,000 miles of ownership. We attribute much of its resale value to the three-pointed star on the grille. It's too bad for Mercedes that the R-Class didn't perform better in the new-car market.

True Market Value at service end: $48,094
Depreciation: $14,021 or 23 percent of original MSRP
Final Odometer Reading: 25,466

Summing Up
Mercedes hoped it had another winner on its hands with the 2006 R-Class. Our conclusions saw it as a mixed bag, and the general public seemed to agree. Sales predictions for the U.S. in 2006 were 25,000 units, yet just over 18,000 examples of the R-Class were sold. For the 2007 model year, Mercedes cut prices by $5,000 in response to the faltering sales, though it continued to offer multiple variations of the V6 and V8 engines.

As we found our long-term test coming to a close, Mercedes announced further cutbacks to the R-Class line. For 2008, a cheaper two-wheel-drive model is an option to the previously standard AWD configuration. The high-dollar R500 and R63 models are being dropped from the lineup completely, making V6s standard across the board.

When the R-Class first entered the market, the least expensive R350 cost nearly $48,000. With this latest announcement, a 2008 R350 is now available for $42,675. Though Mercedes tried hard to persuade Americans that the R-Class could furnish executive-class transport for adults, it's clear that it has been categorized by consumers as simply a family-friendly minivan with a luxury nameplate. Even a successful marque like Mercedes-Benz can't win them all.

The manufacturer provided Edmunds this vehicle for the purposes of evaluation.