slammer111

You want to stay at the maximum torque bit in theory.

I may be no engine expert, but something tells me this also doesn't quite work because when they run these graphs they're at WOT. I would imagine that the sweet spot shifts (with respect to RPM) depending on how much throttle you give. It probably doesn't change around by *that* much though.

pinebaron

31.2 mpg average speed 69mph over 111 mile door to door each way journey last weekend. It's a Bluetec. It's a blast driving the Bluetec.

2slowcdi

I filled up yesterday and for the first time the heads up miles per gallon average was right on the money. Most times it off up to two mpg.
I never fill up unless I have used over a half of a tank, so I don't know if its right on short trips.

djrabbi

i was bored and thought bout this thread......i was looking at my miles left in tank meter.....filled up gas and hit the road

at 60MPH= 499miles
at 65MPH= 504miles
at 70MPH= 493miles
at 75MPH= 450miles
at 80MPH= 403miles

I changed speeds at every 30 miles.....get 65mph is the best

PlatinumPi4u

Awesome!!

So what model are you driving? I'm going to fill up soon and look into this and report back.... (e500 sport)

djrabbi

same here

Dexion

Here's my normal mileage after a 25 mile drive to work, includes uphill, downhill, 2nd gear creeping and one 20 second stoplight. Did 65mph for the most part with drops to 60mph

Garden State Pwky southbound in north nj.


RWD E320 with 99,000 miles
I just changed my air filters and wiped clean the tubes on the manifold. Going to do spark plugs this weekend hopefully I'll crank abit more mpg out of it.

ndasgruv

I believe a lot factors contribute to average MPG. (ie: aerodynamic add ons (wings and things), unsprung weight, & tire pressure) Just did a road trip from SoCal to Laguna Seca Raceway and couldn't better 21-22 mpg...and that was at 75-80 mph with the cruise control!

My car is a box stock E320 with no aerodynamic upgrades. But, it has Brabus sport suspension (lowered about 55mm) with 8.5x20 and 10x20 Mandrus Milleniums running about 40psi. I have to push a heavy a$$ wheel that's wide as as a school bus through the air I know that has a lot to do with my low AMPG. Hope this helps.

Nola

The problem I see is that each subesequent reading has 30 less miles of fuel in it... assuming you read at the end of the run, an approximation would be something like

60 = 499+30 = 529
65 = 504+60 = 564
70 = 493+90 = 583
75 = 450+120 = 570
80 = 403+150 = 553

And even so , the adjustments are run at the cobination of previous speeds so it is not totally accurate.

Where are the mythbusters when you need them.

PlatinumPi4u

Well we should be able to identify the sweet spot by looking at a dyno chart. A dyno which was ran by a vehicle with no mods, bone stock....

Dexion

I can only tell by how far I can travel before each notch disappears on the gas tank. 65mph is my best.

fatherhood

Reviving an old thread.
55 MPH appears to be my sweet spot. That being said I averaged 40.8 mpg on a recent trip doing about 65 MPH. Later in the trip I wanted to see how high it would go and I dropped it down to 55 for a while and I hit 43 mpg average. I could get it higher if did crazy hyper-miler stuff and running on my summer tires jacked up to 35 psi, but I'm pretty pleased with getting 40 mpg with a 4000 lbs luxury car on winter tires just driving conservatively.

Mike_W

Here are a couple of pictures from last Sunday's trip in my 2008 E550. Trip started in Flagstaff, AZ and ended in Orange County, CA. First shot is from Flagstaff to near CA border – all on I-40 (safely shot by wife on an empty straight section of road). Second is in my driveway. No stops for gas. The E550 is amazing - 382 hp in a 3900 lb car and nearly 28 mpg at 80+ mph.
Mike

fila0220

my 4matic e550 avg is 13mpg over 2,000 miles. But i have seen 28mpg on the highway even 29. I remember i tried to hard to break 30 but it never happened

fatherhood

Driving in the city takes a toll on mileage that's for sure. However, you should be able to improve on that 13mpg figure. It just takes an inordinate amount of self control to drive conservatively. I'm not going to get on my high horse here because when I have occasion to drive in the city, be it Boston or NYC, I find myself driving like a complete maniac.

Shaking my head at Mike's post with a picture of a 170 mile trip averaging 82 mph. To average that kind of speed around these parts of the country, the crowded northeast, you'd either get your licence revoked or crash horribly, possibly both.

djrabbi

I am going to be driving 800 miles to ATL for NYE so I will definitely seeing what is my sweet spot. Mine before was between 65-70 but that 82 is AWESOME for open road I am going to have!

P.S. do you have any mods such as exhausts/filters that would effect MPG?

Mike_W

We had a choice of taking I-10 or I-40 home. I-10 is more popular with both drivers and LEOs. I-40 has mainly big rigs who exhibit excellent lane discipline, so that's the way we went. The speed limit on I-40 in AZ is 75 mph - so "Officer, you say I'm only 7 over? Probably just speedometer error, right?"

Mike

fatherhood

Still, kudos to MB for getting almost 28mpg @ 80 mph with a honking big V8!! Not to mention getting almost 35mpg with a 3.2L 6 banger, Dexion. Now I know why the Parisian taxi drivers use the E-class for their professional and personal use.

Mike_W

No - so far only cosmetic mods - but I'm thinking of taking advantage of the OETuning special. Have a great (and fuel efficient) trip. "Officer - I was driving that fast because I'm trying to save the planet!"

Mike

Das Geld 2

115 mph and 5th gear.

RPM"s were at 2100-2300 and I was tapping the gas 1/20 th down just to sustain the speed.

I covered the distance in half the time and saved half the gas I would have used, who knew !

Green E-300 DT

No way my friend.

No MBZs has that tall gearing.

My E-320 CDI has 2.65s X 0.83 times the tire revs equals only 1782 rpms per mile or at 60 mph.
At 115 MPH, that figures out to almost 3400 RPMs.



D

JeffyPooh

When we drove from Nova Scotia to Key West this summer (8600 km round trip), I drove very gently for the first couple of hours and was rewarded with 8.6 L per 100 km (27.3 MPG US). By then we all got bored of fuel-economy driving style, so I drove 'normally' for the rest of the trip and got 10.5 L per 100 km (22.4 MPG US).

The car was loaded close to the maximum weight limit (five people plus luggage).

Not much difference in average speed, big difference in staying off the gas pedal.

Ichabod

Then those RPM numbers would make sense.

06E5004ME

Here are my figures from a month or so ago.

2006 E500 4Matic Estate

Green E-300 DT

Here is what he posted:

"115 mph and 5th gear.

RPM"s were at 2100-2300 and I was tapping the gas 1/20 th down just to sustain the speed."

If he has the same gears as my car (2.65s?) then that would not be exactly correct.

2100 rpms would equal 113.7 kph. (Very close but?)

2300 rpms would be 124.5 kph.

We need to know exactly which car he has, what size tires and wheels it has and what rearend
gears are in his car and which gear in the tranny (five or seven speed) he's using?
He is stating mph, not kph.



D