I~LUV~W140s

I'd like to see what each W140 gets as far as fuel economy goes...

My '99 S320 LWB gets about 18.5 in city, and about 23-24 on the highway. I'm very impressed with the mileage in town, but on the highway, I think it's a bit low for a motor as small as that, but then again, it's got a 3.45:1 rear end in it, and it is 4500 lbs.

Vasir

i get about 17-18 in the city and 27-30 on the freeway... 90% of my drivign is on freeway.

taoh2

my 98 s420 got 23mpg on freeway on 65~85 m/h

I~LUV~W140s

Vasir, at what speeds do you get mileage of that sort?

I've only had mine 3 weeks now, so I haven't got a lot of chances to take it on roadtrips, but on the one I took it on, I was doing about 75-80 for part of the ride up, then I had to cut it down to about 55-65 for the rest of the ride up, because I was in rural Wisconsin. I stopped for gas right before I reached my destination, and I got about 24.1 or so. Now on the way back, in the same sort of driving, I got like 22.7 MPG.

Do these 320s like the lower speeds more or the higher speeds more, as far as economy is concerned? I noticed that at 76mph, that motor is spinning 2800 rpm, which seems sorta high for me. Is the 65-70mph zone a lot better on gas?

Vasir

it depends. i cruise at 80mph at no incline and get ~27mph. but at even a slight increase in the grade the mpg drops like a rock.
when i go snowboarding in the winter, the s320 gets ~8mpg up the mountain.
on the very same hill, at the same speed the s600 will get ~14mpg.
2800 does seem a little high, i get around 2500 rpm. ill let you know after my next drive on the freeway.

whoover

The weight of the W140 means that mileage isn't its strongest suit, and that it gets worse at higher speed. I was amazed at how much better mileage I got from my 2001 S55 than from the 1995 S500 it replaced, especially when driven hard. There are a lot of things to love about the W140, but weight isn't one of them.

Rod Spohn

For what its worth..... After a 220 trip yesterday with about 75% flat and 25% hills I got 22.6 mpg. I drive about 65 to 75 most of the time. This is the first time in a long while I figured the milage in a somewhat controled/sustained enviroment. By the way the temp was about 105 yesterday. A little over a year ago I took a trip in the winter and had more mountains and got just shy of 25 mpg so I think temp plays a big roll.

tirona

i get 18 city / 25 highway

jruerph

I was a little suprised to get 25.2mpg on a 200 mile trek from Detroit to Chicago over mostly flat terrain hovering around 75-80mph at about 70 degrees.

I~LUV~W140s

I went up to Duluth MN this weekend to visit some friends. Now I'd say the trip up I-35 is around 80% flat, 20% incline. On the way up, the temp was in the mid 50's-'60s and I kept it at a steady 75 mph with the cruise on and got 26.7 MPG...very impressive. On the way back down, after doing about 15 miles of driving in Duluth's very hilly terrain, I got like 20.7 MPG....same temperature as the ride up...upper '60s and I kept the cruise control at 75mph too. I believe the reason behind that was I had a decent tailwind on the way up, but I was driving into a pretty solid headwind on the way down..

So between the 26.7 & 20.7, my average speed, at 75mph, with a fairly flat drive, with temps in the mid '60s is 23.7 mph. Not too shabby at all. The car is rated at 17/24 and I'm getting about 18.5/24. Very nice.