dramatically increased MPG! 95 E320 wagon
 

ok

Check your math. If your reserve light usually flashes at 260 miles, you're getting ~16mpg. If it flashes at 300 miles you're getting ~19mph. 30mpg is not happening.

I agree that 30 mpg in a gasser W124 auto wagon isn't happening. I'm only in the mid 20's highway on my 5 speed wagon and thats only because of the extra gear over the 4 speed auto.

its responses like this that make me think my next wagon will be maybe a... Volvo..Youre talking about your 87 300E? no not likely going to get 30..but many report the 26-28 range and the math? no we dont do ANY math with a reserve light but wait till we fill up and then factor the MPG based on gallons taken which is always subject to error.

how you know the gallons consumed at the reserve flash is beyond any science other than the crystal ball. What I know is it went from 260 to 290 and counting, still not on. You dissagree fine, its my car, I was there. If you have no insight dont offer it.

You're the one who stated that you usually have to put in ~12 gallons of fuel when the reserve light flashes on. 300/12=25 In MPG terms, that's a pretty long way from 30mpg. You'd have to do 360 miles on that 12 gallons to get 30mpg.

Why not?

My 1991 300CE regularly returns 35 mpg on a 500 mile <100 mph run. I measure this accurately too, by filling up before I leave and re-filling at the end. Admittedly, our gallons are a little larger than yours but still.

RayH

my heavy s class did 28.5 mpg,with not exceeding 2500 rpms,and timing advanced.

my statement was that the results are uncertain because of fill errors and would prove out, the point is that I had a dramatic improvement and I did/do. My reserve light went from 260 to 290 and still not on, (the reserve light tells nothing about gallons to fill needed, flashes on intermittently and is less than accurate) this is all preliminary to further measurements, AS I SAID. You want to respond to my comment fine, you want to argue with your presumption don't adress it to me. If you think I didnt have this improvement go away. You obviously want to contradict me and I am done with your comments. My post is to invite KNOWLEDGABLE comments about the factors that may be responsible, which I speculate on here..Thanks everyone for the relevant information. I did the math (NOT fro the reserve light but from fill measure) and yes I went from 17 at times to now always over 20 in town, lots of idle time. and on trips, yet to be certain but in the past pushing 30 as many have reported. And as my 94 sedan consistently did, same engine but not an ASR system. And serously Im trying to sort between an 05 wagon in an E320 or a V70 volvo and I find the volvo has many of the same features I chose the mercedes to obtain at about 1/2 the cost and that five cylinder is adopted for many vehicles of other makes. I love the merz straight six but that V 6 isnt so great and the five cyl also has issues but everything I look at under 5K in the mercedes has issues, and a prime 2005 v70 can be had for 5K so...Maybe front wheel drive turbo is the future for me! But I will never sell my 124 with the smooth six and great performance and WELL over 25 mpg on trips! Just cant go Hundai or Kia...euww!

In my case, I find the reserve light to be very accurate on my 124 cars. If I fill the tank as soon as that light is on steady, my '87 wagon takes 16.5 gallons, my '95 sedan takes 20 gallons. I've found this to be very consistent.