hwyngarden

Greetings. We just got an 07 R320 CDI w/ 7000 miles. Loved the car on first test drive, and it's been growing on us more ever since. I'm glad to have found this forum.

I'm curious about the mileage other diesel owners are getting for this vehicle. Our average has been about 21 from a combo of highway and city. We've put about 2000 miles on the car. We've been driving it in the "c" transmission mode. When we were on the highway cruising at 80mph this past weekend, I reset the trip computer so it gave me a newly calculated average mpg. It registered around 22mpg. I know the EPA estimates highway mileage at 55 or 65 mph, which might yield upwards of 30mpg in this car, but I'm surprised it doesn't do a little better than 22mpg at 80mph.

Any observations from other owners would be greatly appreciated--thanks in advance!

silverspecial

Ouch, I get that with my gasoline R350

RDriver

Your numbers seem to be LOW!!! Especially for hwy. Some GL 320 owner(s) posted 29 mpg for a short stretch of highway driving.

Here are mine:
- City driving, avg 25-35 mph: 20 - 22 mpg
- Mix driving, avg 35 - 45 mph: 22 - 24 mpg (40 % city, 60 % hwy)
- Hwy driving, avg 55 mph - 65 mph: 28 - 29 mpg (100 % hwy)
- Hwy high speed, avg 80 - 85 mph: 26 mpg (100 %)

All of my numbers are car computer calculated.

C or S mode have no noticeable on mileage for higway or city. I've noticed a huge improvement on mileage numbers after the breaking period. My numbers are based on more than 6,000 miles driven. The city numbers were in the 17 - 18 mpg during the first 1,000 - 1,500 miles.

Being a used car, check your car tire pressures, oil level, tachometer level at idle should be around 600 - 700 rpm, etc. If the mileage stays unimproved, consider finding/bringing it to a "good" MB dealer.

mitaka

I get 21-23 mostly city w/ some highway. Stop and go NYC driving 17 mpg. All highway 27-28 @ 80 mph. It is pretty amazing considering the size of the vehicle and permanent all wheel drive. My average on the Honda Accord Hybrid in the city is about the same.

Scotsman

Out 350 gets on average around 21mpg but up to 25 on motorways.

RDriver

1 UK gallon ~ 1.2 US gallon.

So your R350's mpgs should be like 25 m/ukg = 20.8 m/usg, and 21 m/ukg = 17.5 m/usg. I've seen GL 450 owners post 20-21m/usg for highway.

Scotsman

Yeah, I'm a bit surprised as our SL gets much better mpg. The R's a big car and 4WD of course.

Azla

I get around 14 km a litre ( 33 or 34 miles a gallon) in my E320 CDI stationwagon

rpringle

If I'm driving carefully and I'm easy on the pedal, I get combined (highway and urban) mileage in the range of 9-10L/100km (23.5-26 mpg US). Driving on the highway at 60-65 mpg, I'll get 8.7-9.0 L/100km (26-27 mpg US) - not sure what driving 80 mph would do but it wouldn't improve.

FL Diesel

I wouldn't trust the trip computer. The best way is to reset the trip computer after a fill up and then divide that mileage by the # of gallons you put in on your next fill up. I think that you'll find that your numbers are a little higher.

Sheri

I agree with FL Diesel. We just bought a 2008 R-320 with 11,300 miles. We filled up before we left Pensacola then filled up again when we got home. We drove 80 mph on the highway all the way home (about 375 miles). We got 25.6 mpg. Considering this was the first time we drove the car and we did not know the area, we are pleased. We were totally loaded down with luggage and people, too. So, I am sure that we will get better mileage in the future.

I've also been driving around town with the average speed of about 35 mph. The trip-meter is saying I'm getting 24 + mpg. We'll see when this tank is closer to being filled back up.

rpringle

Last week I drove Toronto to the US border on the highway. In no rush, I set the cruise control at 105 km/hr (roughly 66 mph) and drove int the right-hand lane virtually the whole way with the air on.

I got 8.0 L/100 km (29.4 mpg US; 35.3 mpg Imp) - fantastic!