170d11 33l/100km without load

[Peterdenmark]

Hi!

I am doing a little trial run around Sweden and Danmark. My first tour with the family.

The consumption is around 33 liters / 100km when driwing between 60 and 76 km

Mostly I have been driving slowly because the tires are not very well balanced so they jump alot at >70kmh.

This seems like a high consumption no? The car is stock and I have very little weight with me.

Also the top speed of 76 on flat road seems very low. Is this normal?

[Ulf H]

... do you use bigger tires than original ... is the speedometer calibrated? ... ist the speed of speedmeter very different to that from the navigatiionsystem / GPS? ...

... Yes, 33 l/100km ist to much for a slow traveling 170D11 ...

Greetings Ulf

[Alter Schwede]

Hi,

33L/100 km sounds a little much too high.

What is the origin of your truck? Dumper, tipper, fire truck?

Did you check the differential locks and if you're on high or low speed gear?


Greets from the Scandinavian "Downunder"

Uwe

[OliverM]

Also the top speed of 76 on flat road seems very low. Is this normal?

Maybe Transfer box in Low range ?

Grüße

Oliver

[Peterdenmark]

Hello. Speed is tested with two different gps.

I have tried to work the lever for the g/s gear but nothing seems to happen. I can hear a "pffff" from the air but I can not see any levers working on the outside of the gearbox. Does the"action" happen inside the gearbox? Or on the differential?

I have also tried to use the lever on a gravel road but the speed did not seem to be much different in the low gears.

I have the original 8.25r20 tires on the car.

It is a firetruck with a 9 person cabin. 1972 with 5 foreward gears.

Thank you for your ideas and replies!

[dave]

hi peter,
that sounds pretty much like the same gear ratio, tire size, topspeed and fuel consumption our magirus170 (from 1971) had, so i guess its all normal. 77 km/h at top rpm is a really low gear ratio, much like constantly driving in second gear with a normal car. solution: mount bigger tires
on 14.50R20 wheels, fuel consumption dropped to an average of 25 l/100 km, absolute minimum was approx 19 l/100 km.
greets,
dave

[Peterdenmark]

Hi Dave

Yes that sounds like a similar situation. Do you use the original rims?

[dave]

hi peter,
we used different, wider rims for the bigger tires. the original rims are too narrow for that tire sizes.
finding the right rims will need some work and/or some money (or some luck) and its one of the most discussed topics here: 8 bolts, proper rim offset, load capacity and clearance for using it at a truck (for example agricultural or construction machines may have fitting rims, but its likely they are not allowed to be used at truck speeds) etc. .
i'am out of that tire-topic since many years, others will have better information.
on the smaller magirus 120 i liked the 12.00R20 trailer tires on rims from the russian SIL 131 (aka "russenfelgen"): very good in the desert and very smooth and fuelsaving on tarmac - but completely useless in wet meadows:
.
greets,
david

[Peterdenmark]

Awesome info, thank you David!