trumpet1

For a 12 cylinder, these cars get pretty decent gas mileage. I went to New Orleans this weekend (close to a 700 mile round trip for me), and I got around 22 mpg! I used 93 octane since the Renntech people insisted on me using that grade.

Just wish I could cruise at 120 mph. The interstate I traveled on had very few cars on it and the road was smooth and straight.

cjf_moraga

Wow.. 22 mpg is pretty good for this engine! So far I have got up to 19.2 mpg on my S600.. still only have 2000 miles on the clock but the engine is probably getting used to me now...

...at the other end of the spectrum on a slow rush-hour crawl up-hill the other day I hit a rather dire 8.9 mpg...

Chris

JRAMGV8

22mpg!!!! Not bad for a V12, im sure your foot was light on the paddle through the entire trip

Chucky300

WOW! 22mpg...

I dont think I get that with my S550 - lol but im driving like a new yorker

lol

trumpet1

Around town I only get maybe 12 mpg. I actually stayed around 80 mph on this trip. Wind was not a factor either. We just had clean air pushed through the south with a nice cold front too, so many factors may have lined up for me. Even in the past though, I've noticed that on freeway trips I was getting 20 to 21 mpg. I now have 16K miles on my car.

jerseyMLdriver

Wait is that better or worse then driving like you are from Jersey?

Chucky300

LOL

Im not sure!!!!!!!

Doctodd33

ive seen 30mpg on my s550 while doing some slow freeway driving to the keys.....all these MB engines have stepped it up. They have to compete with BMW who also makes great engines.

T

WSH

Interestingly, despite all the various mfr claims re: MPG in some theoretic world, in my mix of urban commute/high-speed fwy (w/many "exuberant" mid-range accel bursts btwn clumps of traffic)/mtn twisties driving, I've always gotten about 12MPG, no matter CL63/CL600/SL65/997TT/599....

Real issue w/any of these 12MPG cars isn't the trivial cost of fuel (for guys who commute via $150K+ cars), but the range....where MB's 24gall tanks are critical for commute-useability....and where cars w/<18gall tanks like Porsche, etc become irrelevant b/c of lim range....and cars w/27gall tanks like Ferraris seem daily-useable, until one considers the crashworthiness of their fuel tanks....

cjf_moraga

S600 range is pretty good on one full tank of gas... around 350 miles when my trip computer settles down after a few miles of freeway... though I have not driven that far in one go yet...

You are right of course that the cost of fuel is trivial on a $150K car... but there is a kind of perverse pleasure in eeking out each .1 of an MPG...

Chris

WSH

Very pleased w/MB range

Never drive more than 75mis from SF anyway.....biggest issue is after driving around SF for few days (at a ?8-9MPG clip) and suddenly needing to head deep into SiliconValley for a mtg; hassles of considering fueling (most gas stations nr SF's fin dt have annoying/poss dangerous panhandlers; and no convenient refueling options along 280 until well into SiliconValley).....was driving 996TTS/997TT for a couple of yrs (during my sabbatical from MB) and much appreciated how much more commute-useable are MBs than Porsches w/their puny fuel tanks and 12MPG (and lack of Bluetooth)....

trumpet1

I know it warns not to "top off fuel tank" but I do it anyway. I've done it all my life on every car I've owned and I've never had a problem at all with it. I'm sure it's a safety thing but I don't smoke at all and I don't talk on cell phones while I pump gas.
The one thing I have noticed is that back in 1980 when I topped off it didn't make a whole big difference in the overall price of the tank of gas. Might've added $1.50 to the bill.
Today when I "top off", it can increase the overall price of a tank of gas by around $7.00 !!!!
Today , when the nozzle shut me off, I turned around and looked at the price. It showed $59.50. After slowing topping off, I turned back around and was startled when the final price was $67.25
It put almost 2.5 gallons more into the tank. That is about 50 additional miles I can drive just by topping off.

absent

Speaking of "range" ,it was one of major factors why I got rid off M5.
I just couldn't get more then 160 miles from a tank.
997s also suffer from mediocre fuel tanks.

absent

[QUOTE=WSH;2514222]Interestingly, despite all the various mfr claims re: MPG in some theoretic world, in my mix of urban commute/high-speed fwy (w/many "exuberant" mid-range accel bursts btwn clumps of traffic)/mtn twisties driving, I've always gotten about 12MPG, no matter CL63/CL600/SL65/997TT/599....

QUOTE]
You must be "coasting" a lot or never go over speed limit in your 599 to be in the 12mpg range.
In normal urban/freeway mix it gets only upper single digits....

Diesel Benz

[QUOTE=absent;2520075]The manufacturers figure for my W221 is 8.5 l/100km for mixed/average driving. My current reading is 8.3l/100km, averaged from since the car was new. This equals 28.3 miles per US gallon. I hardly ever fill up before having driven 1000km (about 625 miles).

The W211 does a lot better.

carsnob

I heard that high end Mercedes (550's and V 12's) actually somehow get better mileage at high speeds (assuming there's smooth highway distances) than a lot of other cars. Anything to this?

AsianML

So much power at so little RPM??? The engine doesn't have to work as hard to maintain speed???

What RPM does the S550 and S600 at at 80 mph?

Diesel Benz

No, it does not work like that, although it is a very common statement that driving 100 mph consumes less gas on an engine that "does not have to work as hard". It is obvious that it has to work exactly as hard (I know this is not what you meant), the force needed to keep the speed is not dependent on the engine.

The problem specifically with gas engines is that the efficiency is poor at partial load. The best efficiency comes at almost full load (and close to the max torque rpm). A big engine would make the car go a lot too fast if driven at this engine operating point, and then in order to keep the speed lower, the engine needs to work at partial load.

Of course one has to compare engines having the same technology.

A different thing if the comparison was an S550 or even a bigger W221 against another car brand. There the gain for MB would likely come from the tranny (reaching low rpm at normal speeds, making the engine run closer to max load. Note max load does not mean max power, it is just close to max power at that rpm) and specifically from the low drag body.

cjf_moraga

Asian ML - when cruising at 80 mph my S600 is usually in the 2000 RPM to 2500 RPM zone depending on the gradient... It very rarely hits 3000 RPM on a steep incline... The sheer torque of the engine is well matched to the 5-speed and is so relaxed... it hardly breaks a sweat... not to say the revs don't go up somewhat when I point and shoot...

I get mileage in the 17-19.2MPG range at around 80 mph... Using the distronics cruise control can stretch the MPG's as well... (Obviously no human non-linear gas pedal foot twitching)

Chris

WSH

[QUOTE=absent;2520075]Don't have 599 any longer....IMO, world's leading perf car today if one doesn't risk-adjust for safety....if Ferrari ever develops competent/advanced passive safety engineering/systems, CL's would be largely irrelevant....

Was being generous/imprecise w/the fleet avg 12MPG; my point is/was they're all roughly same MPG, despite varying claims....in urban-only short (<<5mi) commute use, any of these cars are 8-9MPG; high-speed fwy w/bursts of mid-range accel maybe 10-12MPG.....don't track MPG very closely but my sense is CA fuel yields 1MPGish less than ex-CA fuel (rough comparos vs NYC colleagues)...and cold temps/lack of engine warm-up (either short urban commutes or ex-CA winter weather) tend to also drop MPGs 1-2 MPG....

Suspect avg speeds on SF Peninsula's 280 fwy (one of SF-SiliconValley's key commuting arteries, connecting an upscale residential suburb called "SF" to the SiliconValley economic epicenter) are among highest of any economically-relevant urban fwy in world (incl Germany)....esp if considering CA weather allows higher yr-round speeds....very similar distances, 40mi+, ala Greenwich-Manhattan or LkForest-Chic, w/far faster traffic flows in SiliconValley, even in rush hr.....a rather remarkable phenomenon to enjoy for those familiar w/annoying traffic patterns in various major urban regions (many car guys who moved to SF from NYC marvel at concept of actually looking fwd to one's early AM commute on 280 at robust speeds w/rather scenic adjacent vistas of mtn ranges, often w/fog rolling over mtns.....unique stuff) .....

Agree....key is relevant range.....MPG is amusing.....poor range and/or dubious fuel tank crashworthiness are deal-killers IMO....