DavidNJ

Ok, US gallons. My first entry is below. It was going from Chimsee on to Munich on the Autobahn. It was raining. The car was loaded with 550 pounds of people and luggage. The windows were closed. The AC was on.

We had a flat so we were on a space saver spare. The cruise was set at 50 for most of the trip. And I am pretty good at manuvering in traffic to maintain a steady speed (you should see me on Third Avenue in Manhattan!)

cdiken

It spins faster because it has a smaller diameter. Good way to trick the computer into thinking the car is going farther than it actually is, leading to the computer sptting out a high MPG.

The best I ever had was babying it at 64 MPH on a flat 50-mile run, got as high as 37.5 mpg but that's about it. That run was with driver + 1 passenger, no luggage, no headwind, no air conditioning, and tires pumped up to 40 PSI.

DavidNJ

I thought the diameter is the same as stock. I think the mileage is due to the low speed (less wind resistance), constant cruise control (no acceleration/deceleration), and maybe the weather (the moisture making the turbo more efficient).

glojo

I was always of the opinion that it is much more economical NOT to use cruise control.

A very light right foot, good forward observation, and plenty of anticipation is the way to go. (plus if you really want to be frugal, no airconditioning, no fan, windows closed and to be really frugal, no radio).

Since we have had diesel vehicles I have never worried about economy. Enjoy the moment and live for today.

Good luck though with your mileage figures,

John
Some sunshine with showers in Torquay

DavidNJ

Cruise control is a steadier hand than your foot. Distronic would be even better. In the old days, cruise may have been worse. These days, I don't think it is.

They key is to never touch the brakes. That simply wastes energy, turning it to heat. The only advantage over cruise maybe on the '05s and with Distronic, the cruise will apply the brakes on down hills. With the diesel, the high compression may minimize that a bit. However with a gas engine, it will probably kill some energy on downhill runs.

johna1

Is that green light on the right of your picture to indicate that your headlights are on?

DavidNJ

It was raining

MBE55AMG

I believe those are the low-beam lights.

saffrontiger

DavidNJ Good to see you are enjoiyng your new CDI. Your input here on this forum has been helpful for me puyrchasing my CDI four months ago.
As for bedt mileage, I've done 40.6 miles/gal over a 20 mile run. AC on, cruise on and 74 degress at night. I've found that keeping it under 70mph gives optimal mileage. Flip side...flying down the highway for a short sprint at 130mph. The car handled well, was solid as expected and I felt it could have gone even faster. I didn't have the brass ***** to go faster. Mileage during that short stunt was approx 27 mpg.

cdiken

Yes it can go faster, but I thought US models were governed to 130?

glojo

I hate pushing the point but cruise control is a nice motorway or long distance option. It will however NEVER be as economical as a good driver, with good forward planning, good observation, good anticipation and good braking sense.

Are vehicles fitted with automatic gearboxes as economical as there manual counterpart? (modern automatics are very good indeed)

Does the US offer advanced driving courses for everyone that solely wishes to improve hteir driving skills? It is something I would thoroughly recommend. For those that have taken them they will verify how they are not going to turn you into Mario Andretti, far from it. They are all about roadcraft and offer excellent value for money.

Regards,
John
A very nice sunny morning in Torquay

justin w

On the mpg figures....

Typically getting about 37-40mpg on 100mile / 70mph trips now....

270CDI/AUTO/cruise mostly/300miles from new....

justin w

Sorry last post wrong 3000miles not 300 miles.....

Oops

DavidNJ

Justin W, aren't your gallons bigger? If you are using Imperial gallons, that would be 31-33 mi/USgal.

John, the anticipation allows you let the cruise operate uninterrupted. I can't imagine a driver who is steadier than cruise. And while manuals don't have the power loses of an automatic, in practical driving, with a lockup torque converter and a typical US spec car (over 180hp), I don't think most drivers get better mileage with a manual. There is a tendency to over-rev an engine with a manual.

Adoption of auto-shifting manuals, like VW/Audi DSG, will probably ice the argument, removing any automatic advantage.

glojo

[QUOTE=DavidNJ]
It is obvious we are never going to agree. My wife always gets better mileage with cruise control disconnected, as does my son. As I would imagine any competant advanced driver would.

On Top Gear (a motoring program) they used the very latest Audi A8 4ltr diesel and drove from London to Edinburgh AND return on one tank of fuel, giving a fuel consumption of just over 40 miles per gallon. Everything electrical was switched off INCLUDING cruise control The journalist commented that the cruise control was switched off because it is NOT as efficient at saving fuel. The 'claim' by Audi for the A8 is
Urban driving 20.7mpg,
Extra Urban 36.6mpg
Combined 28.8mpg. It is usually the combined figure that is most accurate, but in my experience even this is sometimes optimistic.

I am not criticising your driving, but you are digging your heels in on something that is accepted amongst professional advanced driving instructors.

If you look on your BMW site that will give you fuel consumption figures for similar powered vehicles with either the auto or manual gearbox. No doubt once again you will disagree with the figures, but they are there for all to plainly see.

My Sprinter has the gearbox that you are describing, in the Sprinter range it is called the Sprintshift. A really excellent piece of technology that is indeed more fuel efficient than a standard automatic gearbox, our large heavy goods vehicles also have them and they are getting more and more popular, but as you rightly state they are described as an auto-shifting manual gearbox (MB = Automated transmission 'unquote')

If you ever get the oppurtunity of taking an advanced driving course, I would thoroughly recommend it.

Your claim about drivers over-revving there cars that have a manual gearbox says more about the particular drivers lack of ability rather than the vehicle. (In the UK if you take your driving test in an automatic, you are then only allowed to drive vehicles fitted with an automatic gearbox)

Sorry for the disagreement and as I have stated at the beginning, we are not going to agree over this point.

Regards,
John
Advanced Institute of Motorist
Advanced Motor cycle instructer (sadly retired)
Class 1 HGV Driver (retired)

DavidNJ

I don't think we will agree. Most automatics upshift at the slightest provocation, keeping the engine at extremely low revs. Most manual drivers, at least here in the US, keep enough revs on the clock to go when they press the right pedal.

No doubt, an manual gearbox is much more efficient than an auto box. But unless the driver is consciously trying for high mileage, it isn't there. IMHO.

That doesn't mean someone trying for high mileage can't get it with an manual. And if you are willing to turn off all the electrics, and coast down hills, I'm sure you can beat everything. But is that real life?

After the start of the first US oil crisis in 73, Ford ran an ad with TV personality Hugh Downs where he got high mileage in a full size American sedan. Of course, his trip involved coasting down 5000 feet of elevation!

Now we can back to high mileage CDIs!

David

P.S.
Only the MB and Yukon XL, both only available with auto boxes, have auto boxes.

glojo

To use Cruise Control or not to use Cruise Control?

Finally watched a documentary where the intention was to drive as economically as possible. This test was carried out on a British motorway using one vehicle. When Cruise Controil was engaged the vehicle averaged 32mpg at a constant 50mph over a one hour period. With the cruise control switched off it averaged 40mpg at a constant 50mph over the same road and for the same one hour period with the same driver.

Cruise control is obviously a brilliant 'comfort' aid, but this documentary confirms my personal belief that using cruise control will not be as economical as a good driver using forward observation and anticipation.

Happy New Year to everyone,
John

A very damp, mild afternoon in Torquay

DavidNJ

Possible, however on my commute, the cruise holds 34 miles/us gallon +/-.5mpg on the highway, and I can't equal it.

David

khaug

At ~3800 miles:

Overall average: 29.9 mpg (per trip computer)

Best calculated trip mpg: 36.1 (Lansing, MI to Dayton, OH and return - 75 mph cruise)

I installed 4 snow tires 2 weeks ago, and my mileage has dropped by c. 10%. The diameter of the tires is the same as the oem "green" Michelins, so the rolling resistance of the snows must be a bunch higher!

Messerchmidt

once the warrenty exp. get a chip for the cdi, 240hp e320cdis rock...

www.upsolute.com

they should have something for the american spec car soon

SAguirre

I am glad that you also found a drop in MPGs when you installed the winter tires. I did not exactly get a drop, but I plateaued. I am maxing out at 26.9 MPG on my gas E320 4 matic, but my tires are very aggressive Blizzaks WS 50s. I was expecting to get better MPGs by now, but I figured that the plateau was due to the sticky snow tires.

BTW, I personally can always gat better fuel economy without the cruise on. My Audi is a stick shift, and the cruise sucks more gas on it too. I rarely use the cruise since I drive in the mountains and I hate it when the car downshifts doing uphill. When I drive it by foot, I can either avoid the downshift all together or at least downshift sooner and not strain the engine at the last minute.

When I drive through the plains of the US going out east I always use the cruise. Simply to avoid getting a speeding ticket.

Steve

Green E-300 DT

It all depends on where the spacesaver tire was mounted!
If memory serves, David had it mounted on the right rear.
This means that the odometer was still spot on correct.
If the smaller space saver spare were to be mounted on the right front, then the odometer/speedometer would
be wrong, recording faster than actual speed, and showing his vehicle traveling further than it actually did. :p

Now perhaps if the diameter was slightly less, the gearing was changed a little, but at that low of a speed and rpm, there wouldn't be that much of a difference.

Isn't 50 mph less than 1500 rpm? That's below the beginning of the maximum torque curve.

RickCDI

My E320 CDI is only a couple weeks old and I am averaging almost 34 MPG between city and hyway driving ....about half and half of each. Now I am using the C cycle on the trans as directed by the manual. average hyway speeds about 70-75 mph.