jctevere

Thought I would create a thread that shows some of the "real-world" MPG that we are seeing in the coupes - especially since these are new MB engines.

Here is what I just got on my most recent run with my C250 coupe:


I would say that this was a 80-90% highway trip. Pretty awesome results. I am looking forward to increasing this number when we get into warmer seasons as there is less ethanol in the fuel as they switch to "summer fuel" instead of "winter fuel". Also, in my previous w204 mercedes, after about 1,000-1,500 miles I got signifigantly better fuel economy (only at 500 miles now). I hope that it is the same with this car - my goal is to pass the 40MPG mark and show that you don't need to sacrifice luxury or need hybrid drivetrains for those numbers.

I achieved this by having the cruise control set on 62MPH. I will try different speeds to see what the "sweet spot" is for the c250 engine, but this is a great start. On my prior w204, I couldn't seem to get the same economy when I manipulated the car's speed with the accelerator (ie: without cruise control), even if I was very light/careful. So definitely use cruise control when you can!

slktyperice

This is pretty good. I'm assuming you're using 93 or 94 octane out on the east coast. We're on 91 octane in California and I'm thinking it's good for about 1-2mpg. Here's what I get:

On stock rims:
Daily Commute (30 miles, 25 miles on highway no traffic): 29-32mpg
Daily Commute (30 miles, 25 miles on highway with traffic): 24-29mpg
Vegas trip (260 miles, no traffic): 32mpg

On 19" rims:
Daily Commute (30 miles, 25 miles on highway no traffic): 27-30mpg
Daily Commute (30 miles, 25 miles on highway with traffic): 23-27mpg
Vegas trip (260 miles, no traffic): 30mpg

This is all on Eco mode and minimal pedal-to-the-metal action.

jctevere

Yup, ALWAYS 93 octane, and I always try to get Sunoco gas if I can (I just prefer them, also somehow by far the CHEAPEST where my office is... I pay $3.83 for 93 including credit (its same price cash/credit). BP,Mobil near that station is 3.87 + 10 cents for credit. Near my house I can't find premium from reputable gas stations for less than $3.95 (not including credit)...

I am running on stock tires/rims. I am going to be putting on my 18" Zinik Minardi rims wrapped in Continental Extreme Contact DWS soon since winter/snow is approaching. Kind of anxious to see how the RWD coupe will perform in the snow with the DWS tires!

Try to use cruise control next time, I am sure you can improve those numbers. Once you understand it, its VERY easy/convenient to use.

Push upwards to engage at current speed, and then it uses a similar system as the blinker stalk for increasing speed. One click up/down is 1mph change (respectively), or you can push further past that first click up/down to get a 5mph change (respectively). To disengage either press the brakes, or push the stalk forwards (towards the front of the vehicle).

slktyperice

Yeah I bet the extra couple mpg is from the increased octane. I'm curious to see what kind of results you get with the DWS's. Just keep in mind that all-season tires merely mean mediocre performance in dry/wet/snow. We've done some extensive testing with the DWS and because of the softer compound they use to get the good snow traction, treadlife is highly affected. My friend got through a set of DWS's on his E46 M3 in less than 7,000 miles in daily driving. That's probably an extreme case but you're probably lucky if you get over 15k on the rears.

I don't like using cruise control. Same system as the one in my old R171 SLK350 but the way I drive is a bit too aggressive for cruise control (plus I like to coast to save gas).

jctevere

I'm shocked that you feel that way about the DWS tires. They are rated as some of the best on tire rack as far as tread life. In fact, on my SL500 I got 50k miles out of one set! I usually run them higher pressure than normal though to make up for the slight dead on center feeling at the recommended 30PSI, so I keep them at about 35PSI front, 36PSI rear. Perhaps your friend either had alignment problems, improper tire pressure, unable to rotate, did burnouts daily, or drives like a maniac, but I don't think that those results are "typical".

And yes, an all-season tire will not perform as well as a winter tire in heavy snow and especially ice. The rubber compound is not as designed/made for freezing temperatures as a winter tire. But I can't say enough about the performance of DWS in the WET! Simply amazing, just as good, if not better than in the dry. And while the dry performance isn't as good as Michelin Pilot Sport A/S I used to have before the DWS, it is just as good as OEM tire equipment in the handling department on dry - and MUCH smoother/quieter.

MercZ

The last 2500km / 1550 miles (high-way and city driving) I averaged around 6l/100km what according to google would be 39.2 MPG.
But just last week in a higway trip of 190km / 118 miles I did 5,4l/100km (43.5 MPG), trying to maintain a constant speed between 130 - 140 km/h (80 - 87 mph).



The low average speed reflects the beginning and end of the trip while in the city, so I guess it would be around 105 miles on higways and 13 in the city.

Car is a 170hp C 220 cdi Coupe!

Glyn M Ruck

Octane rating of fuel will not change mpg achieved unless the car is running perpetually with timing retarded due to measured knock from the knock sensor. Density of the fuel will have the major influence on mpg. Density is an effective measure of energy value as long as you can completely combust the product.

If Octane rating of the fuel is boosted by alcohol addition the typical mpg will be even worse. Lower energy value & partially oxiginated.

The M271 Evo turbo is certainly frugal. Those are our findings in SA even with the ultra lean burn switched off.

ralawren

C350 - first 4500 miles averaging 25.6 mpg
about 1500 on a couple long trips, the other 3000 in mixed conditions outside of Washington, DC

I am very impressed, even better than my 128i.

GuOD

My C350 is not doing so great... I think I average about 12L/100kM

johnny--2k

my drive is mixed freeway but with a lot of traffic, average over the past 1500 miles is about 22mpg. Beats the 15 that I was getting with my Cobra!

AV1

Do any owners of the C250 diesel coupe market variant have numbers to show on their consumption, would also be interesting to compare the real life figures of those compared to the literature

MercZ

Well, I don't think the C 250 cdi figures should be too different from my C 220 cdi, afterall it is the same engine..
I'm getting between 5.5l/100km to 6.2l/100km (42.77 to 37.94 mpg).

AV1

Thanks for the info MercZ

Here in Australia literature for the C250 CDI states a combined cycle of 5.1l/100km and 6.7l/100km for the C220 CDI, so the numbers for your C220 are not too far off.

Is the C220 CDI engine exactly the same as the C250 CDI ?? I thought the C220 was only a single turbo as compared to the C250's twin sequential/staged turbos, so maybe that's how the C250 gets a better economy number when just cruising on the initial single small turbo

jctevere

The C250 CDI now having twin turbos definitely helps bump the fuel economy. However, I believe it is only part of the story. The other enhancements are due to the new 7 G-TRONIC "PLUS" transmission which uses new fluid and new TCU settings and slightly redesigned architecture to help improve fuel efficiency. So between the additional turbo and the new transmission, the C250 CDI is able to achieve this increase over the C220 CDI.

AV1

Thanks jctevere

So is the new blue efficiency C220 CDI also twin turbo still curious about that one

I just read up on some more literature and found that the new blue efficiency C220 has a combined cycle of 7.0l/100km in real World conditions, not too far off the claim of 6.7l/100km

Still wanting to hear from C250 CDI owners on their consumption figures

MercZ

The C 220 cdi is also twin turbo.



That literature is very different from what we have here.

AV1

Thanks MercZ that answers all my questions ^^^^

Here in Aust. all blue efficiency C Classes only get the 7g-tronic, the older 5g-tronic has been dropped.

jctevere

Yeah, that clears everything up. The "blue-efficiency" badging is on all vehicles (petrol+diesel) regardless of fuel economy figures on all 2012 and newer that have the new revised 7G tronic Plus transmission (at least to my knowledge) - unless it is ///AMG - then I only see the side badging for that engine.

Ubiquitous5

C350 Coupe w/ 1 Passenger:

Highway w/ No Traffic @ 70mph: ~27.5mpg
Highway w/ No Traffic @ 80mph: ~27mpg
Highway w/ No Traffic @ 90mph: ~26mpg (Drove to Vegas & Back)

City ~17

Blessed_Badger

Here in the UK, in my C250 CDI I'm getting an average of about 40mpg (brim to brim), indicated as 43 on trip. This is mainly back and fro to work (10 miles in each direction and a mix of A roads and stop/go traffic) and short trips at the weekend. The outside temp makes a big difference to the diesel. At less than about 2C the stop/start doesn't switch on until I'm nearly at work (8-9 miles), when it's above this (definitely at 5C or 6C) it's active by the first junction (after about 1 mile of travel). The stop/start makes about 10-15% difference to the journey from what I've experienced.

On a very leisurely trip to the Lakes over Christmas, with the cruise set at 70mph I got 50mpg (real (trip said 54mpg)). I did experiement with setting it to 56mph (the supposed ideal) but the fact that I was being overtaken by caravans, lorries and a Robin Reliant (I kid you not!) meant that this didn't last long - I found that the trip said I was doing nearly 60mpg during this. It definitely wasn't enough of an improvement to warrant the grief off SWMBO or the embarrassment of driving at that speed on a motorway in a £40k Mercedes.

To be fair, overall it's been about what I expected - i.e. way off manufacturer claims, but miles (per gallon) better than my 3.0TDi Audi A5.

I am however hoping this will improve as from what I can gather due to unsuitability of stop/start in cold temps, the extra engine work for heating the car, and additives to the diesel to stop it freezing all make a big difference to cold weather mpg. Roll on the summer!

MercZ

If your talking of UK mpg I would say it is very similar to what I am having on the C 220 cdi.

40 UK mpg = 33.3 US mpg = 7 l/100km
50 UK mpg = 41.6 US mpg = 5.6 l/100km
60 UK mpg = 50 US mpg = 4.7 l/100km

Although I dont think I have ever reached 4.7 l/100km, the minimum I got was 5 in a short relaxed trip.

AV1

Those are encouraging numbers, even better than alot of small lightweight and small engined petrol vehicles, certainly looking forward to the improved efficiency over my petrol cars

mis3

So, my CLK320 is getting slightly better mileage than C350.
I make the 500 KM (one way) trip frequently and my highway mileage is 29 MPG. I usually set the cruise at 110 kmh, 68.3 mph.

I was expecting better fuel economy with these direct injection engines.

tharsis

Average over the last week for my car (still new, not fully broken in, less than 900km on it yet and most importantly still before it's first service)

250CDI

Tuesday 6.3L/100km
Wednesday 5.9L/100km
Thursday 6.3L/100km
Friday 6.1L/100km
Monday 5.8L/100km

Average "since reset" still getting lower, started at more than 7.8L/100km

Note driving to/from work figures only, so "real world" every day drive for me.

Generally speaking my perception is that it's getting lower and lower over time, weekends I tend to throw it into sports and fang it a bit more so it hardly counts!

It will be very interesting after i go through the first service though.... Even still, without it i'm better than a damn Prius!

tivoboy

The 250 SHOULD do pretty good, this is that. The CDI should do even better. With a US C300 at about 70 MPH on highway, I get a good 29-31 with constant driving.