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R320 CDI Mpg?

38K views 16 replies 15 participants last post by  GLOPRO 
#1 ·
What are people getting for their fuel economy on the '07 R320 CDI? I was thinking about getting one of these versus getting another E-Class because of the great value for money, they don't seem to be selling very well and dealers seem to be flexible on them.
 
#2 ·
I've had my R320 for 6 weeks now and love it. Tons of room and unbeleivable milage for a vehicle this big.
I've been averaging about 9.6 l/100km (24mpg us, 29 mpg imp.) and that is mostly city driving. I can get it down to 8.0 (29 mpg us, 35 mpg imp.) crusing at 110km/hr on the highway. And to top it off Diesel is .06 / litre cheeper than regular gas here in Canada and about .16 cheeper than premium.
Saving a ton of money on fuel!!!
 
#3 ·
Be Prepared for Lower Window Sticker Fuel Milege Figures on 2008 Models

Starting with 2008-model vehicles, the Environmental Protection Agency is revising its tests to better reflect real-world driving conditions. Kiplinger has developed a tool to provide an estimate of what the new EPA fuel economy numbers will be for about a thousand 2007 models under the new tests.

City mpg will be reduced by 12%, on average, and highway mileage will shrink by 8%, according to EPA estimates. Gas-electric hybrids and some other high fuel economy vehicles could see even bigger reductions.

Current standards were developed back in the 1970's, when cars and driving styles were far simpler. The new standards factor in higher speeds, stop-and-go driving, more aggressive acceleration, use of air-conditioning and driving in colder temperatures.

The new standards will more accurately reflect "real world" fuel mileage instead of the inflated figures that most vehicles never achieve. While the new testing methods provide more realistic figures, many will be in for a shock when they see the lower fuel mileage figures. For example, when comparing the current 2007 model year fuel mileage figures to the 2008 model year, the EPA fuel mileage figures on the window sticker for the R Class will now be (No CDI Figures Yet):

------------------2007------------------------2008
------------City--------Hwy--------------City-------Hwy

R350-------16----------21---------------14---------19

R500-------12----------19---------------11---------17

R63--------12----------16---------------11---------15
 
#5 · (Edited)
I have an R320 since the first week of March with about 1,500 miles driven.

My average MPG is around 24 miles/gallon, which is 60% city and 40% highway. The AC or Heat are always on, settings for all three zones around 68-70-72. A month ago diesel price was $0.05 more than premium unleaded (91 oct). Now diesel is $0.05 below regular unleaded (87 oct) and almost $0.30 below premium unleaded (91 oct). Miles between fillups are well over 500 miles / tank.

Real Sweet. :thumbsup:
 
#6 ·
Depends a lot on your driving style

Recently, I averaged 24.1 mpg in my R350 on a 310 mile round trip from New Jersey to Maryland on the interstate highway. My average speed was 62 mph and I had the airconditioning set at 72deg F, the outside temp was 82 deg F.

I found that accelerating steadily, as opposed to stepping on the gas unnecessarily and keeping in the middle or right lane with cruise control set at a steady 70mph and slowing down (instead of coming real close to the vehicle in front and braking) when there was traffic ahead, went a long way in getting this rather impressive figure for such a heavy vehicle. I did however, do some short stretches at 80mph and even tried 95mph for a few minutes - the 24.1 mpg figure includes these short high speed runs too.
 
#10 ·
8.4L/100km or 28 US mpg on highway ... sweet!

Getting about 11.4L/100km or 20 in the city. Not so great. But where I live, there's lots of stop-and-go driving.

Ultra-low sulfur diesel here in western Canada is considerably cheaper than Unleaded, usually about 15% less.

Very happy with the engine & transmission on this car. Beautiful piece of engineering, IMHO.
 
#17 ·
Im in Sydney Australia and did a 12hour round trip and saw 8.4 -8.5 through winding roads and AC on.

And this weekend i just drove up another 900km with the OEM roof racks and OEM Large roof box. This time the car was fully laiden with 2 adults and 4 kids plus about 25kg in the roof pod.

I managed 8.4L/100km (~28mpg) pretty impressed!

Im using Caltex Vortex Diesel.
 
#12 · (Edited)
R320CDI Fuel Economy

I have a 07 R320CDI with 13,000 miles that I picked up in March. You raise a good question regarding highway fuel economy after break-in -- soon after I got it (less than 500 miles on odo) I drove to Florida from Pittsburgh PA and got only 25 mpg and was fairly disappointed. After 3000 - 4000 miles on the odometer, things really picked up. I have made at least a half a dozen major road trips in this vehicle since. On perfectly flat terrain with 100% interstate driving, I can get 29 mpg. In hilly/mountainous terrain, I get 26 - 28 mpg. Around town, I get 18-20 mpg. In highway driving, I typically drive 70-75 mph on interstates using the Distronic cruise control (fantastic option!) almost constantly and with gentle acceleration from start. Driving this vehicle aggressively will definitely hurt fuel economy!

As a caveat, I use a diesel fuel additive, which claims (among other things) to improve fuel economy, but I'm not sure by how much (I doubt it's a big effect). Nevertheless, I do think diesel fuel quality makes a difference -- I've seen some trips where I've gotten 5-10% better economy than the previous trip on identical terrain at identical speeds. If you research diesel-fuel quality, you'll see it's far more inconsistent than gasoline quality.

Overall, I consider this an outstanding highway cruiser and the diesel-engine's fuel economy is a big bonus. However, I must say that the availability of diesel fuel can be an issue so you really must plan on when and where to re-fuel. I usually always start looking at a 1/4 tank -- only ~40% of the stations within 10 miles of my house carry diesel. On the interstates, I usually can find it at roughly 75% of the interchanges, but even then there are still fuel stations in the US where the highway signs say they have diesel, but it's low-sulfur fuel and not the ultra-low sulfur diesel that Mercedes mandates. Even then, some stations that carry ULSD have big fat filling nozzles that can be used on heavy-duty trucks but do not fit the Mercedes. All in all, the fuel economy and huge amounts of torque to me more than make up hunting for fuel every once in a while, but I know some people don't want that inconvenience.
 
#13 ·
R320 fuel economy

Great! Thanks for the report. I have a 2005 VW Passat TDI Wagon and get 38-39 on the highway. I would love to get a little bigger vehicle but want that fuel economy too - I want my cake and eat it! Ithin the Benz, for it's size gets great economy - I think I might wait a year or two - thanks again!
 
#14 ·
We have 07 R320 CDI with 8k miles on it. It averages out at 24MPG in the Northeast. On highway around 28 and city varies from 19-23. On short trips (cold days), I noticed that if I let the engine warm up, it gives better mileage. I thought by now all diesel sold in US is ULSD.
 
#15 · (Edited)
The EPA is giving stations to 2009 to completely convert over. Some truck stops have low-sulfur only (I imagine that's because I hear bitter complaints from people with old-tech engines that ULSD gives them problems). While usually it's not a problem for me (I usually can find non-truck-stop filling stations that have ULSD), I ran into a problem 2 days ago at a busy interchange that had only truck stops and all of them had low-sulfur only. I had to drive 20 miles further to find a station at an interchange with ULSD.
 
#16 ·
Pretty well broken in!

I have an '07 R320 CDI, and I will cross 24k miles today. I am seeing about 26-28 MPG combined on my commute. I drive approx 62 miles each way, with about 80% highway. Most of the highway is at 75-80 MPH, without cruise. I find that if I use cruise, my mileage actually decreases, since on a downhill the system will brake, which wastes all of that energy.
 
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