Thread: Tow vehicle motors

Here is food for thought, if diesels were no good they wouldn't be in trucks, then try and keep up with a truck at night.

But road speed and economy towing 2-3 tonne on a trailer, surely you can't be serious, I would err on the side of caution and forget the road speed, how quick will you be able to stop something like that.


john

Hi Guru

I owned a boat (sold late last year) that was 2.8t total road weight. Our previous 4*4 was a ’94 300tdi manual disco that happily towed it all over the place. I will add that my version of happy may not be the same as yours – highway I sat on 90 and it hung on well on the hills ie once rolling it was happy - but it was (worse than) dreadfully slow off the mark around town.
The injection pump had been “tuned” (Highway Diesel bne) - after that it was one gear better on hills, (highly recommend). Towing economy was around the 17 – 19L/100, essentially double what I got normally (low to mid 9s – the advantage to being slow).
Never had a cooling problem but I think the disco radiator would be larger than 3.5 rangie. And on the braking point my trailer was setup with one of the latest Electro Hydraulic marine systems through 12’ discs on all wheels and the total package pulled up nearly as well as the empty car – however it did take a while to get all the adjustments right in the beginning and I always used a HAYMAN REESE load distribution hitch to help with stability and put weight back on to the front axel of the car.

Its really going to be a personal choice V8 auto v tdi manual – its sure going to be different.

The heaviest load I've towed with my manual 300Tdi was about 2.5t (a series 2a with spare motor on a car trailer) and it struggled to reach 80km/hr on long stretches with a slight uphill incline. And I remember using second gear on some hills. We also had a 15.5ft caravan (full height and full width) and we were down to 60km in some places when the incline and the wind was against you. We now have a camper trailer, which weighs as much as the caravan, however we can tow happily at 110 if there is no wind. So I think at lot of it comes down to the aerodymanics.
Now we are thinking about a bigger caravan again, and whilst the disco could tow it, we like touring holidays where we do 600-800km per day, and that just aint gunna happen with the 300Tdi/caravan combination (too slow), so we are also looking at more powerfull towing options. We have a 3.5 EFI Rangie also that we havent towed much with, but judging by it's normal road going acceleration (or lack of it) I suspect it wont be much better. And then there is the whole range thing (I like to have at least an 800km range when towing).

Cheers,
Taz.

The heaviest thing I have ever towed was a broken down Prado and my truck towed it at 100k's no sweat but on hills and around corners it was slow.Saying that a 8o series towed it first before braking a cv joint and it was slower by a long way.Power is not a issue,stopping is. Pat

I've had a 300TDI Disco and my current TD5 and have towed car trailers with both of them. I always thought the 300TDI was the better tow package. Not as good at high speed cruising while not towing but definately a better vegicle to tow a heavy trailer with. It would hold 5th gear easily on hills where the TD5 needs top go back one or maybe even two gears.
Regards,
Tote

I tow heavy car trailers with buggys (probably 2.5T - 3T) with my 3.5L EFI V8 Auto rangie. It tows well and gets about 300kms per tank (about 21-22Lper 100km) It holds road speed pretty well too.

That is pretty good economy for a heavy tow. I don't think that my 300tdi would do much better. Same issue with the power. You may be disappointed with the minimal gains for the conversion outlay. Unladen is another matter though.
Tony

With such a heavy load I'd put an auto in instead of a manual, taking off from a standing start will be a killer, especially if on a hill.

Baz.

Originally Posted by JohnE

Here is food for thought, if diesels were no good they wouldn't be in trucks, then try and keep up with a truck at night.

john

Diesels are different, however the comparison of the 300TDi 4 cylinder and a modern diesel semi trailer is like comparing chalk and loungeroom furniture. It wasn't so long ago that diesel trucks always held up the traffic and crawled up mountains at walking pace. The modern semis have huge 500+ BHP turbo V8 engines and more importantly are designed to tow such loads. The 4 cylinder 300TDi needs to have additional cooling to safely tow the weights you are discussing.

Diana