Fuel tank capacity (bluetec) mystery

[MB500]

I am completely surprised to learn that, according to the manual, the gas tank capacity for E350 bluetec is 80 liters or 18 gallons. I looked at the log of all fill ups (6 in total) and they were all over 19 gallons. In fact, one was 19.4 gallons. Am I going to wrong gas stations?

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[hx_guy]

You're math is off. 80 liters is 21.39 gallons (3.74l per gal.)

[hyperion667]

Originally Posted by hx_guy

You're math is off. 80 liters is 21.39 gallons (3.74l per gal.)

[listerone]

Although the official literature I've seen has been a bit confusing...it makes reference to a "reserve" amount...I've alway assumed it was just over 21 US gallons.I've had my BT down to almost zero a couple of times (or so I've assumed) and the most it's ever taken has been 19.8 US gallons.

[ColdCanuck]

Originally Posted by MB500

I am completely surprised to learn that, according to the manual, the gas tank capacity for E350 bluetec is 80 liters or 18 gallons. I looked at the log of all fill ups (6 in total) and they were all over 19 gallons. In fact, one was 19.4 gallons. Am I going to wrong gas stations?

Actually it is 80 l.

which is 21.4 US gal or 18 Imperial gal. or 0.335 hogsheads (US) or 0.2444 hogshead (Imp)... you get the picture

[ImInPA]

Speaking of which have you checked the price for a hogshead of Premium these days?

[ColdCanuck]

Originally Posted by ImInPA

Speaking of which have you checked the price for a hogshead of Premium these days?

I just had my second $100+ fill in the car, gas ain't cheap on this side of Canuck land.

Glad my other vehicle is a hybrid, so I can go nice or go cheap(er)

[Live Oak]

Originally Posted by ColdCanuck

Actually it is 80 l.

which is 21.4 US gal or 18 Imperial gal. or 0.335 hogsheads (US) or 0.2444 hogshead (Imp)... you get the picture

Not to be a pedant (but to be one), a litre is .264172 US liquid gallon. Thus, 80.1 litres = 21.160181 gallons.

Eh?

[ColdCanuck]

Originally Posted by Live Oak

Not to be a pedant (but to be one), a litre is .264172 US liquid gallon. Thus, 80.1 litres = 21.160181 gallons.

Eh?

But is that corrected to 15 deg C ??


I don't know if any of the rest of you have that kind of pricing, but one of the newer ways the oil companies have to [s] gouge [/s] enhance profitability is to adjust the apparent volume of gas pumped as if it were at 15 deg C (which of course is 59 F)

[MB500]

Guys,

Sorry for the confusion I might have caused. I pulled up a British User Manual on line and sure enough it said 18 gallons on the Specifications sheet. But this is due to difference between the US and British gallons. It now makes perfect sense !

Now, I think that my Low Fuel indicator (the yellow one) goes off way too early. I once filled up the tank right after the yellow light came on and it only took 18 US gallons to fill it up. So, this makes the reserve of 3+ US gallons. That would give me close to 75 miles of driving in the city (I have Bluetec).

[ImInPA]

Only 75 miles on 3 gallons? Something else must be off too.

[hx_guy]

Sounds about right to me.

My low fuel light also comes on when I have approx. 3 gallons left I would estimate because the estimated range shows around 30 miles left usually, and I keep driving, and then the second warning comes up on the center display (the one where it no longer shows you the range, but a picture of the car with a fuel pump next to it) and that is usually when I fill up and it takes right around 19 gallons.

[BenzV12]

Originally Posted by ColdCanuck

Actually it is 80 l.

which is 21.4 US gal or 18 Imperial gal. or 0.335 hogsheads (US) or 0.2444 hogshead (Imp)... you get the picture

WOW, what a technical post
I like liters , dislike galons always leads to confusion

[MB500]

Originally Posted by ImInPA

Only 75 miles on 3 gallons? Something else must be off too.

I would be very curious to learn what mileage you get on your Bluetec. I get about 23-24 mpg city driving but it gets up to 37-38 on a highway.

[Green E-300 DT]

Originally Posted by hx_guy

You're math is off. 80 liters is 21.39 gallons (3.74l per gal.)

One US gallon is exactly 3.7854 liters, so wouldn't 80 liters be 21.1338 gallons?



Derrel

[Live Oak]

Originally Posted by ColdCanuck

But is that corrected to 15 deg C ??

I don't know if any of the rest of you have that kind of pricing, but one of the newer ways the oil companies have to [s] gouge [/s] enhance profitability is to adjust the apparent volume of gas pumped as if it were at 15 deg C (which of course is 59 F)

Actually, 15 deg C (59 degrees F) is the standard for measuring fuel capacity. Check aircraft fuel capacity standards, for instance. No "gouging" going on. And it's not "new."

When you think about it, since fuel is almost invariably stored in ground, 59 degrees is not far off what you would expect on ~almost~ any normal day. There has to be a standard, and 59 degrees is a pretty good one.

Long range pilots of the long past used to fill their tanks in cold storage buildings at airports. They'd then hurry like hell to taxi and take off before the warming fuel blew the tops off the tanks!

[Green E-300 DT]

What I would like to see is for all of us to post actual tank averages and not what the computer says!

I always do better by the computer, but when I fill mine and do the math the old fashioned way, mpgs are always less.



Derrel

[Live Oak]

Originally Posted by Green E-300 DT

What I would like to see is for all of us to post actual tank averages and not what the computer says! I always do better by the computer, but when I fill mine and do the math the old fashioned way, mpgs are always less.

You are so right. On a recent 3,000 mile trip, my 2011 E550 road mileage was 28.9 measured at the pump. The computer said I got 29.9. The difference has always been about that amount. (70% interstate, mountain west and desert driving.)

[Green E-300 DT]

Originally Posted by Live Oak

You are so right. On a recent 3,000 mile trip, my 2011 E550 road mileage was 28.9 measured at the pump.
The computer said I got 29.9. The difference has always been about that amount.
(70% interstate, mountain west and desert driving.)

Your extremely high fuel economy leads me to think that maybe you
forgot some of the gas you added during your long 3,000 mile trip.
Do you know how much higher than the EPA estimates that is?
The EPA lists yours at but 23 mpg on the highway.

When I figure tank mileages, the figures are always less than what the computer will say!

Start a Fuelly and record each and every tank and let us see how you do please.

Yours is the older 5.5 L motor. The 2012s have smaller engines at 4.7L and
are listed as doing better than yours, even though they are 4-matic.



Derrel

[Live Oak]

Originally Posted by Green E-300 DT

Your extremely high fuel economy leads me to think that maybe you forgot some of the gas you added during your long 3,000 mile trip.
Do you know how much higher than the EPA estimates that is?
The EPA lists yours at but 23 mpg on the highway.

Start a Fuelly and record each and every tank and let us see how you do please.

Yours is the older 5.5 L motor. The 2012s have smaller engines at 4.7L and
are listed as doing better than yours, even though they are 4-matic.

Derrel, for starters you are implying that I don't know what the hell I'm doing. You are wrong!

Each and every tank and mileage was recorded.

I'm not about to send you the spread sheet. And I'm not about to do your "fuelly" and send you results. My trip was a "fuelly," as you call it, and you have the results.

I did the identical trip, even to hotels occupied, a year earlier. The average for that 3,000 mile trip was 27.1 (vs. 28.9 this year). I attribute the difference to high winds on the earlier trip and possibly to a car barely broken in.

FYI, the EPA numbers are "estimates" and based on dynamometer tests, at EPA specified speeds, and assumed calculations to simulate real-world conditions. You will see many comments here on road trips far exceeding EPA highway mileage ratings.

[listerone]

Originally Posted by Green E-300 DT

The EPA lists yours at but 23 mpg on the highway.

The EPA rates mine at 33mpg highway.On a couple of occasions I've gotten 38mpg on *long* stretches of Interstate under less than perfect conditions...conditions like A/C on full blast (105 degrees) or when using winter diesel (which gives lower mileage).And yes,I used the fillup-to-fillup method to calculate and didn't forget to log any fuel bought.

[Green E-300 DT]

Originally Posted by listerone

The EPA rates mine at 33mpg highway. On a couple of occasions, I've gotten 38mpg on *long* stretches of Interstate under less than perfect conditions...conditions like A/C on full blast (105 degrees) or when using winter diesel (which gives lower mileage).
And yes, I used the fillup-to-fillup method to calculate and didn't forget to log any fuel bought.

Yours I do believe! Not the 38 mpg for true tank averages however. Computer yes, but tank mileage, no. I have seen mine report as high as
45 mpg running on a long trip from Sacramento to LA, but it did not do nearly that amount when figured out fuel used for those miles traveled.

Why is the 33 mpg correct? Because it is 'right on' with what many others on Fuelly record.

When someone tries to say that they drove 3K miles with a big V8 gasser (5.5L) and got tank mileages
of 28 plus mpg, well that is simply too much and not believeable and I do not except that!
If that were true, no one would be buying diesels.

Ask why MBZ dropped down with the E-550 (5.5L) to a smaller 4.7L for the currect model.
They were after better fuel economy, and IF the older 5.5L was doing as well as some here claim, why would they have gone smaller?

Post your true fuel economy on Fuelly. That is how to report true fuel economy!



Derrel

[ImInPA]

Originally Posted by MB500

I would be very curious to learn what mileage you get on your Bluetec. I get about 23-24 mpg city driving but it gets up to 37-38 on a highway.

The lowest I have seen in my BLetec is 28 mpg. Te Hihest is 44 mpg. Now I have close to 40k on mine, so it is almost broken in.

[listerone]

Originally Posted by Green E-300 DT

Yours I do believe! Not the 38 mpg for true tank averages however. Computer yes, but tank mileage, no.

Allow me to clarify.On two different occasions,one just a month or so ago,I've done long stretches on an Interstate,cruise control set at 70mph,in which I've gotten about 38mpg.Both times it was a fillup to fillup calculation...the computer was much higher both times.Both occasions featured less than perfect conditions for high mileage,as noted.One was in January using winter diesel which,as you may or may not know,gives noticably lower mileage than does summer diesel.In the other it was 100+ degrees the whole time and the A/C was on full blast the whole time.And BTW,I've only claimed these results to be on long runs...not for an entire tankful.

Feel free to believe that I'm either lying or that I flunked 3rd Grade arithmetic if you wish.

[thekurgan]

Originally Posted by listerone

Allow me to clarify.On two different occasions,one just a month or so ago,I've done long stretches on an Interstate,cruise control set at 70mph,in which I've gotten about 38mpg.Both times it was a fillup to fillup calculation...the computer was much higher both times.Both occasions featured less than perfect conditions for high mileage,as noted.One was in January using winter diesel which,as you may or may not know,gives noticably lower mileage than does summer diesel.In the other it was 100+ degrees the whole time and the A/C was on full blast the whole time.And BTW,I've only claimed these results to be on long runs...not for an entire tankful.

Feel free to believe that I'm either lying or that I flunked 3rd Grade arithmetic if you wish.

I've seen the same, Listerone. My on board computer listed at 44mpg, it was actually 38 when calculated via pump stats and mileage. 70 cruise set, a/c on, 4 passengers total, no luggage. As the engine breaks in more, I see the mileage fluctuate a bit. The car does NOT like stop-and-go in the heat with the a/c on, I see only 24-25 in on those tanks where I'm in town. My weekly commute is 90% highway.