[MV] Re: Underpowered UNIMOG

Colin Brookes (colb@xtra.co.nz)
Tue, 27 Jan 1998 07:03:54 +1200

In message <m0xwOkV-0003ZQC@fwd14.btx.dtag.de>, Andreas Mehlhorn
<a.mehlhorn@t-online.de> writes
>> The Unimog has quite good offroad capabilities as far as not bottoming
>> out (short overhangs), however it is drastically underpowered and this
>> needs to be kept well in mind all the time.
>>
>
>For which reason do you need a lot of power off-road? To turn the
>wheels and throw the mud?

There is a difference between a 'lot of power', and my comment that it
is underpowered.

>If you are in real heavy off-road conditions, you drive slowly.
>5 mph or so, sometimes slower. And for this speed you don't need
>much power. You need a gearbox which offers a wide range of gears
>for slow speeds.
>

crawling about the countryside at 5 mph holding up other vehicles in
joint manouvres didn't strike me as very practical. To use an engine
for off road 1.5 ton load carrying that relys on nearly 5,000 rpm to
achieve only 80 hp, surely must strike you as a bit odd. Put a 20%
reduction in rpm due to drag off road, and you are down to about 35 hp.
Compare that to the FV1604 ordinary old 'box radio truck', the same
rated Nato 1.5 ton, of the same period, with an engine achieving 98 hp
at only 3,750 rpm.....that's about twice the torque power output for the
same rated vehicle. For load carrying in off-road (difficult terrain),
it's bottom end power that is req'd, not hp at high rev's.
The GFR field car, the 'Munga', suffered the same fate as the 'Unimog'.
Nice performers when empty, it's little 980cc 3 cyl engine screaming
like a lawn-mower. But pick up 4 x 12 stone paratroopers each with 68
lbs of kit plus weapons and ammo from a DZ and it's quicker to get out
and run from the exposed field of fire. It's no surprise they eventualy
replaced it with an update of the incredibly successful Kubelwagon from
two decades back, the VW181 (first 1500 and then uprated again to
1600cc).
It must be born in mind that Criteria effecting military decisions are
often different from one place to another, as well as one period to
another. The Criteria for that period in the GFR, with 'The Airlift',
still clear in everyones minds, was fuel economy for mass produced
field equipment (field cars and small load carryers). It's not the
criteria for the US collector, or performance off-road.

>If your aim is to win the PARIS-DAKAR Rallye, you need much power
>off road, but if you want to drive in really difficult areas, where
>all other vehicles surrender, the good old underpowered UNIMOG is
>first choice.
>
>Regards
>Andreas
>

Not if you have real experience of their capability. That one extra
gear does little to improve it, let alone the extra drag losses it
incurs.

regards
Colin Brookes
Invicta Military Vehicle Preservation Society (IMPS)
colb@xtra.co.nz

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