dennishuynh80

I've been getting 11 mpg in the city and an average of 14 mpg on city and highway. what can i do to improve this? i've tried changing out my spark plugs and wires, but no difference. my car has 110,000 miles.

homeofstone

sounds about right for city. Maybe be lighter with the foot. Its a big V8.

vettdvr

Sounds like plugged cat converter. I AWAYS got 24.5 or better on 93 octane with ethanol

Craftysince86

i thought i was getting bad gas mileage and I'm getting about 20mpg average, my 108 does better than 11mpg in city.

servicetech

I get around 22mpg with 70% city and 30% highway. have you checked your air filters too?

malahhaor

seems too low. back when i had clk500 and s500 i was averaging 17+ in mostly slow moving suburb driving. After a tune i could do 28+ on highway.

ajohnfar

Been Having this same problem, i'm averaging 10 mpg city and 13 mpg highway. Car seems to be running fine other than the mpg and the damn airmatic system.
What kind of problems u guys havin at 90k miles.

Michael.Sinz

My 2004 E500 has over 134K miles on it and in my normal short (urban) drives to/from work I get around 18MPG. Longer trips (highway miles) tend to get around 24-25MPG. (Usually at 70MPH or more)

SilverTiger

The best I have seen on the Hwy at 75mph is 22mpg. Have yet to do a tank just around town. I would love to find a way for better mpg. My wagon has 24k miles.
Suggestions?

Michael.Sinz

Note that I think the E500 wagons have lower mpg than the sedans. Especially the 4matic vs rwd

dennishuynh80

could it be the mass air flow sensor causing poor mileage?

KEY08

definitely something wrong. I am 17-18 city pretty regularly and 22 highway this time of year in cold Chi Town.

sk8erjosh09

My swap is 3140lbs with me in it and I get 13 in town, 28 on the highway. A lot of it is my right foot but it still seems low for in town. I have new plugs, oil, coolant, everything except air filters (not too bad of a condition) and I'm missing the tubes for cold air, just running hot until I get the SS tubes I have coming with K&N's.

djrabbi

i got 20s on highway so might want to check out cats or have a flush done. City was around 12-13

JayDee4711

The E500 Wagon was only sold as a 4Matic in North America. Mine gets between 16 and 18 MPG with 70% highway. Pretty constant over 45k miles from when I bought it @ 75k. The best I ever did on a long haul was a little over 21. I have just had the spark plugs swapped. Will report in case that makes a measurable difference.

I drove around with the Airmatic stuck in high for about two weeks (see https://mbworld.org/forums/e-class-w...r-message.html). Interestingly, that cost me 1 - 2 MPG, probably due to worse aerodynamics. Should have less impact in the city than on the highway, though. Therefore: Lower ride = better gas mileage.

Michael.Sinz

Driving home from a school function (I am a coach), I noticed that I was getting reasonable MPG (this was after getting off the highway).

The interesting bit is that I was in "parking-lot" traffic for the first 10+ minutes of the drive home.

Here is a photo of the dash of my 2004 E500. Not bad MPG for a big V8 with a 137K+ miles on it. (Most of the trip was at 70+ MPH as that is the local speed limit on the highway.)

dennishuynh80

I changed out my spark plugs, all my air filters, and even cut off my muffler to save 70lbs. still getting 11-12 city and 17-21 mpg up/down grade and 14 average. the only thing i can think of causing this is the mass air flow sensor or the fuel filter/pump. my e55 gets about 12-13 city and 17-18 mpg in dead stop traffic.

LemonSqueezy

LOL dead stop traffic for me = 9.5 average in 4 hours with my 550.

AMGAffalterbach

In the city I average about 15 and on the highway about 19-21 in my 550. If I TRY to drive conservatively I get 18 city and I've seen as high as 27 highway, however it seems like you're getting E55 or E63 gas mileage - way too low.

LemonSqueezy

I guess in a packed city full of hills, EPA mpg doesn't apply to me lol.

AMGAffalterbach

LOL that's true too, except for traffic I don't know what would keep me from tearing up those hills all the time, with the thrust of the E550 I feel like it's a roller coaster or a plane about to take off when I got WOT up a super steep hill.

LemonSqueezy

Plus c63 mufflers makes my foot a lot heavier..

AMGAffalterbach

I had no idea you had C63 mufflers! That's awesome, those things sound like thunder from the factory it's amazing. I remember at the end of our Christmas eve church service I was walking back to the car and a C63 coupe started up in the cold right as I walked by it... wow.

LemonSqueezy

Those mufflers were the very first mods I ever did to my car. Got em off a brand new 2011 c63. They didn't even fit my luxury style bumpers with no cutouts but I didn't care. And yes, cold starts are mesmerizing

AMGAffalterbach

I bet in the parking lot of the dealership too just lifted them right off the C63s on the show room floor eh? My muffler delete and j-pipe was an early mod too, it makes for a much heavier foot I completely agree.