earlybird

I get about 20 mpg (14L/100 km)in the city, depending on traffic conditions. But on long highway trips, I usually average around 38 mpg (7.5L/100 km).

On a recent road trip, I filled up in New Jersey and drove to Toronto without stopping for gas. I was driving on fumes by the time I reached my destination - 31 miles left before empty, according to the computer.

So, with my C300 manual, city mileage is not that great, but highway mileage is impressive.

LandSeaAir

My dads S550 with the 5.5 V8 averages about 20-21 with a mixture of highway and city driving, a good 70-75 mph cruise gets us 28, 20 seems low for a 3.0 V6, are you driving in sport mode or comfort? Comfort may save you some. I guess just focus more on your driving style and try to be as efficient as possible.

ucfbeta92

My first reaction when I saw 38mpg was a dropped jaw wondering what in the heck I was wrong with my car. Then I compared your L/100 km numbers with Acapulco Bill's chart and 7.5L/100km should be 31.363 mpg and 14L/100km is 16.801 mpg. 31.36mpg sounds plausible, even though I've never hit those numbers.

bringtherain

I'm driving in comfort already due to the break in period and trust me, I drive like a grandma as it is due to gas saving habits from my old C. I had a CL-type S for a short while as a beater and that thing was a god send to be honest. 3.2L V6 with 260 HP giving me 24 mpg SPIRITED DRIVING. I'm sorely disappointed in my new C to say the least

IGB

I have been religiously logging every fuel purchase I've made on for my C300 for the past 16 months or so...

Average MPG: 20.31

This is @ 50/50 City/Highway driving.

I think OP needs to be a little more patient, while you are not likely to see a big change from what you're getting now, I don't think 2 fill-ups and only 600 miles on a new engine is even close to a fair assessment!

IGB

Heck, that's better than the manufacturer' rating of 18/28...

Cruise control will certainly help with highway mileage... And hence why you're probably getting those 28mpgs on there. Within the city, and at least for me, cruise control would be on but it wouldn't be set.

Helms

People usually average around 16MPG in a C300, i would consider 20mpg as a very good fuel economy for a C300.

earlybird

oops...my original L/100 conversion was to Imperial gallons instead of US gallons. So you correct in revising my highway mileage to 31.363 miles per gallon.

ltcinf

Just about to turn 20K miles on my 2010 C350. 2 weeks ago went on a 1800 miles round trip road trip. My avergae speed recorded for the entire trip was 75 mph with and average mpg of 30.5. At one point during the trip just on the highway on was between 31 and 32 mpg while maintaining an average of 85 mph--you definitely getting better mpg at those higher sustained speeds.

Last week back to the national capital region traffic averaged 24 mpg on my 70 mile r/t commute. Not bad considering I am not one to go lightly on the gas pedal moving through traffic.

I recall the first few K miles where my mileage was not so good. Seems these MB engines loosen up quite a bit after break-in.

Carsy

"you definitely getting better mpg at those higher sustained speeds."

Not in my experience. High speed travel will increase air resistance ( friction) & increase fuel consumption. About 50 mph is more like the optimum.

ucfbeta92

all good. I wish we could get 38mpg with our cars.. now wouldn't that be something!

Sportstick

Sure would! It would be an A Class!

ucfbeta92

So last weekend I fill my C300 and get on the highway for a ~40 mile drive to the dealership. Kept an eye on the mileage because I filled up at a Chevron instead of the usual (Shell) per SA's recommendation.

And I notice it keeps going up.. first 27, then 28, then 29, until it hit 30mpg! Never saw it go that high before, so I had to take a picture. I was doing 70-80 mph almost the whole time since I got on the highway. And the range was a whopping 564 miles. I just had to snap some pics and share them here..

I'm going to stick with Chevron for a while to see how things are over an extended period of time. And I know that the 30mpg had less to do with Chevron/Techron and more to do with steady acceleration on a highway and not having to brake and accelerate all the time.

Sportstick

Welcome to the neighborhood!!

(P.S. Costco Premium)

ucfbeta92

DANG!

Sportstick

LOL! But, in fairness, some factors go both ways.

Helping me: Manual trans, lower ambient temp
Helping you: Lower average speed

We can probably each do better yet!

itsLoonie

Hmm, my 2008 C300 Sport doesn't have this consumption bar.
Did they add it on the 2009+ models? Not that it matters but I'm just wondering.

ucfbeta92

The temperature's a big issue here in Florida. When it's 90-100 degrees outside, you better believe the A/C is always running and sometimes on full blast.

When you are on "Trip" in your instrument cluster and you're cycling through, do you just not see the consumption bar, or do you not see the range either?

I think they changed the consumption bar a little on the 2011 (maybe even as early as 2010) - as I recall, the bar doesn't go as high as 80mpg.

itsLoonie

It shows the mileage range but no consumption bar at all. Oh wells, need to pay attention to the road anyways or I'd be looking at the bar the whole time trying to see how high I can get it up to the end.

victort

i got mine to show 30.2 mpg on trip computer also! i was soooo shocked! i never even got that high on cruise control set at 75 going from LA to SF!

dcjwlee

Mine seems to hover around 19-23mpg depending on how my day is going...

jctevere

The highest I ever got was 31.8 MPG on the trip indicator. It was a 30 minute trip and I left the cruise control on 60mph the entire time.

Is it just me or does MPG consumption appear a bit funny. I can feather the crap out of the throttle and try to get as efficient MPG as possible, but I still can't get anywhere near the cruise control MPG numbers...

ucfbeta92

My experience is typically the same as yours (jctevere), but when I hit 30.0mpg, I wasn't using cruise control at all.

I've wanted to hit 400 miles on a tank (city/hwy mix), but the closest I got was around 390 before chickening out because I'd been driving on the car/fuel-hose icon for almost 20+ miles. I normally fill up right around 350-370 miles.

I thought this would be tank to hit 400-450 miles, what with the 30mpg ride (by the end of that trip, I was at close to 80 miles, and still doing around 29mpg). Then I had to do the map update with the car running in park for 2 hours..

xolinlevh

New worst MPG, 10.1! bout 10 min on freeway, to the house, then 2.5 hours in the driveway installing the new maps

icanectc

Just did a check my commute is mostly highway but a lot of DC lights before highway about 28miles with an average speed of 50mph per the from start information i got 25.1MPG that was in C and not using the engine for breaking. (which I normally use) and that was with me driving to see how good i could get it. I will try my commute home with normal driving habits and see how good/bad it is.