45 mpg W124 300D - it's in the math - Page 2 - PeachParts Mercedes-Benz Forum

Jeremy5848 · #16 07-08-2009, 03:11 PM

Quote:

Originally Posted by Shawn T. W.

. . . lI bought a ScanGaugeII for my gmc pu, it plugs into the OBDII port, and gives you instant read outs, it "Teaches You To Drive" effeciently! same as any car with a instant mpg gauge, watch that and you will see you are letting off the go pedal as you go up the hill to keep the mpg high! . . .

I put a ScanGaugeII on my '96 . . . my wife watches the mileage constantly. She says the fuel flow number even decreases if she shifts into neutral at stoplights . . . she can get it down below 0.25 gallon/hour, I don't remember her lowest number.

In any case, driving habits definitely make the biggest difference in fuel economy. I have been watching the "Economy gauge" (gasser vacuum gauge) that I boogered into my W124 diesel (put it in the transmission vacuum line) and definitely see better mileage when I make a point of keeping that gauge as consistently low as possible. Once I have my boost gauge installed, I'll have that to watch as well.

With my sick engine, I doubt I'll ever get over 30 MPG but it will be interesting to see what others do.

Jeremy

hobbitss · #17 07-08-2009, 06:13 PM

Quote:

Originally Posted by Jeremy5848

I put a ScanGaugeII on my '96 . . . my wife watches the mileage constantly. She says the fuel flow number even decreases if she shifts into neutral at stoplights . . . she can get it down below 0.25 gallon/hour, I don't remember her lowest number.

In any case, driving habits definitely make the biggest difference in fuel economy. I have been watching the "Economy gauge" (gasser vacuum gauge) that I boogered into my W124 diesel (put it in the transmission vacuum line) and definitely see better mileage when I make a point of keeping that gauge as consistently low as possible. Once I have my boost gauge installed, I'll have that to watch as well.

With my sick engine, I doubt I'll ever get over 30 MPG but it will be interesting to see what others do.

Jeremy

Big Scangauge II fan and it does help with your driving style...
My E300d at cold idle shows 0.3 gph, warm idle shows 0.2 gph, putting it in neutral at a stop light drops fuel usage to 0.1 gph when warmed up...
Take your foot off the go pedal at highway speeds and the mpg meter shows 9999 as the car slows down...

t walgamuth · #18 07-08-2009, 07:43 PM

The taller tires will help your fuel consumption just like changing the rear end ratio and that along with driving fifty five makes me believe your number.

Who can stand to drive fifty five though?

Shawn T. W. · #19 07-08-2009, 08:42 PM

Quote:

Originally Posted by t walgamuth

The taller tires will help your fuel consumption just like changing the rear end ratio and that along with driving fifty five makes me believe your number.

Who can stand to drive fifty five though?

Exactly my point yes if his tires are 1.5" taller they will weigh more . . . but once they are moving you will see lower rpm for the same speed if you had been using stock tires . . . yes there also will be a lack of "jack rabbit start" proformace . . .

I don't mind driving 55 today, or any day, but now when I get on the "big road" I bump it up to 65-70!

As the speed limit is 75, and most people push that a tad, I just smile as they drive by, and say I'm glad I'm not buying thier fuel . . .

Of course when I was on the Autobahn . . .my wife was screaming most of the time for me to slow down

(Well, it seemed like all the time!)

t walgamuth · #20 07-08-2009, 09:40 PM

The extra weight is negligable to mileage but will make it ride rougher and not grip the road as well on bumpy roads.

Hatterasguy · #21 07-08-2009, 11:14 PM

Quote:

Originally Posted by Shawn T. W.

Exactly my point yes if his tires are 1.5" taller they will weigh more . . . but once they are moving you will see lower rpm for the same speed if you had been using stock tires . . . yes there also will be a lack of "jack rabbit start" proformace . . .

I don't mind driving 55 today, or any day, but now when I get on the "big road" I bump it up to 65-70!

As the speed limit is 75, and most people push that a tad, I just smile as they drive by, and say I'm glad I'm not buying thier fuel . . .

Of course when I was on the Autobahn . . .my wife was screaming most of the time for me to slow down

(Well, it seemed like all the time!)

My usual cruising speed in a good Mercedes is 80-100. Depending on cops, and the road of course.

Last year coming back from a GTG, I ran at 90-105+(most of the time over 100

) for an hour trying to keep up with an S600. Mileage for the diesel was still good even at triple digit speeds.

FYI the S600 got high teens, even though it saw very deep triple digits more than a few times on that run. I thought that was excellent mileage for a 6L V12, running at or near WOT.

a2t · #22 07-08-2009, 11:44 PM

Quote:

Originally Posted by oldsinner111

Well I've gotten 1200 miles on one gal. diesel fuel.

Hahahha. With wvo its possible to get an infinite number of mpg D2, just keep it running.

I netted over 140 mpg D2 on my last tank

Ofcourse Im running wvo for last 50k miles. Dear God, if i was getting paid over 6mpg I'd be retired by now. Surely wvo must be the end all be all in a big rig...if you can find enough of the stuff. Just take routes thru the "stroke belt" and you will find more than enough.

Driving a wvo benz has totally corrupted my fuel saving strategy. Everywhere I go its at full throttle, ac blasting. I get into my wifes Escape and net 18 max. That tiny SUV is surely keeping OPEC well funded

moon161 · #23 07-09-2009, 08:17 AM

Quote:

Originally Posted by a2t

Hahahha. With wvo its possible to get an infinite number of mpg D2, just keep it running.

I netted over 140 mpg D2 on my last tank

Ofcourse Im running wvo for last 50k miles. Dear God, if i was getting paid over 6mpg I'd be retired by now. Surely wvo must be the end all be all in a big rig...if you can find enough of the stuff. Just take routes thru the "stroke belt" and you will find more than enough.

Driving a wvo benz has totally corrupted my fuel saving strategy. Everywhere I go its at full throttle, ac blasting. I get into my wifes Escape and net 18 max. That tiny SUV is surely keeping OPEC well funded

Commercial greasers are on the QT, unless they make alternative hiway tax payments.

Shawn T. W. · #24 07-09-2009, 08:27 AM

Quote:

Originally Posted by a2t

Dear God, if i was getting paid over 6mpg I'd be retired by now. Surely wvo must be the end all be all in a big rig...if you can find enough of the stuff. Just take routes thru the "stroke belt" and you will find more than enough.

Well back in 92 6mpg was "Good" for a big rig! and since it was not my truck & and they bought the fuel . . . I could not see dumping wvo (if I had known about it at the time!) in, as all I had to do was get over 6mpg which was easy for me. How much wvo do you think you would have to collect to boost it some . . . and how much time was involved colleding & filtering . . . just to get $0.01 per mile

I drove 3000 - 3200 mi per week avg . . .

Shawn T. W. · #25 07-09-2009, 08:31 AM

Quote:

Originally Posted by t walgamuth

The extra weight is negligable to mileage but will make it ride rougher and not grip the road as well on bumpy roads.

Tom,

What I meant was that on take off it would be affected as more mass to get turning . . . but would probably work out to .001 mpg (depends on how often one took off from a start . . . aso larger diameter tires would also reduce acceleration, so you would use more fuel to get up to speed, but . . . once up to speed . . . you could gain it all back and then some, assuming one stays at highway speeds for the majority of the time.

tbomachines · #26 07-09-2009, 08:41 AM

The other day I saw a chevy caprice that had actually been raised to fit twenty-something inch rims underneath it....actually come to think they could have even been thirty they were so effin large

. Just another case of the rims being worth more than the car....sigh. I do wonder how lethargic the thing was off the line though, those cars weren't fast to begin with.

t walgamuth · #27 07-09-2009, 08:48 PM

Quote:

Originally Posted by Shawn T. W.

Tom,

What I meant was that on take off it would be affected as more mass to get turning . . . but would probably work out to .001 mpg (depends on how often one took off from a start . . . aso larger diameter tires would also reduce acceleration, so you would use more fuel to get up to speed, but . . . once up to speed . . . you could gain it all back and then some, assuming one stays at highway speeds for the majority of the time.

'
You are right. It will hurt acceleration two ways, one it will create more mass to overcome with the heavier wheel, and two it reduces the effective gear ratio making for slower acceleration. I did not mean to sound as if I disagreed on those points.

It might reduce economy around town driving too, but I doubt it.

The taller tires will also reduce braking leverage and thus braking ability as well.

babymog · #28 07-09-2009, 11:11 PM

Larger diameter tires are an old trick to improve fuel mileage by increasing effective gearing. It usually helps at the expense of some off-the-line acceleration.

Hip001 · #29 07-12-2009, 12:50 PM

Miles per gallon is miles / gallons added. Miles per diesel is miles / gallons of diesel added reguardless of what else they happen to be running with it, a skewed figure and totally crap!

I do like the taller tire idea but it would have to be only the rear tires right? What is the speedo hooked to?

babymog · #30 07-12-2009, 12:59 PM

Transmission output (rear wheel speed). Usually front and rear wheels are all replaced, but not with nutty larger, just a little bit.

My father used to commute to Chicago from Michigan (AA pilot), was always trying new tricks to get the big-block engines to burn less fuel, an early user of syn-oil and high-pressure radials.