I do have cc on my rangy even when I'm not towing my 26 caravan and I have a long hill it will as you say jump to third rev the bollox off jump back in to fourth lock up and die . After it did it the first time I realised what it was intended for motorways ect

As with any driving right gear at the right time whenever I'm Approaching a decent hill a quick flick down to third and the problem is solved it does say this in the handbook on automatics I had never used cc I learnt fast.

What the D1 owners handbook states on using cruise control and is only applicable to a diesel engine disco fitted with an auto box, I don't see anthing relating to towing while using CC

"On diesel engine vehicles fitted with automatic
transmission, some fluctuation of road speed
may be experienced when cruise control is in
operation at engine speeds below 1600
rev/min. In these circumstances, move the
gear selector lever to position ’3’ to limit
automatic gear changing to the first, second
and third ratios".

I often use CC at 30mph zone as I have a 6 mile stretch near me that I can complete sometimes without slowing down, but once or twice the box has drop into second on a slight incline but then changes quickly changes back up, no problems if CC is set at 35mph though..
Being an auto I have no top gear untill till around 53mph.

discool said:

What the D1 owners handbook states on using cruise control and is only applicable to a diesel engine disco fitted with an auto box, I don't see anthing relating to towing while using CC

"On diesel engine vehicles fitted with automatic
transmission, some fluctuation of road speed
may be experienced when cruise control is in
operation at engine speeds below 1600
rev/min. In these circumstances, move the
gear selector lever to position ’3’ to limit
automatic gear changing to the first, second
and third ratios".

I often use CC at 30mph zone as I have a 6 mile stretch near me that I can complete sometimes without slowing down, but once or twice the box has drop into second on a slight incline but then changes quickly changes back up, no problems if CC is set at 35mph though..
Being an auto I have no top gear untill till around 53mph.

Click to expand...

I meant it tells you in the hand book that in town ect and winding roads that 3 and sport mode are the better options including hills didn't mean cc I use it too as you know in a 30 she will roll that's why third is better

thebiglad said:

And in any case Ian knows I'm right really, he just doesn't want to admit it.

Click to expand...

<irony> But of course </irony>

Actually I don't think we differ very much. But I will continue to tow using CC where I think it's appropriate.......

thebiglad said:

Don't use cruise control while towing. If you can't work that out for yourself maybe you should consider whether you are sufficiently competent to tow or not.


Dave

Click to expand...

I've been towing large caravans all over Europe with my 300TDI auto for the last 12 years of my 30+ year caravanning hobby. One of the key reasons for choosing an auto TDI was that it is fitted with cruise and I've passed many a happy (if slightly boring) hour on French / Spanish / Swiss roads with the aircon on & cruise engaged travelling to my holiday destination.

In always using cruise wherever possible (including on 'A' roads in addition to motorways) my experience is that - due to the engines torque curve - it works best at actual (not indicated) road speeds of over 55mph (which, on my car. is an indicated speed of 60mph). Used like this my car (a 160K miler with over 50K miles of towing in the last 12 years) is still happy enough pulling my 'van up quite steep hills without dropping out of cruise. If however you engage the cruise much below an actual 55mph the engine's torque simply isn't enough to maintain the momentum, resulting in a sudden loss of speed / power and the cruise dropping out...

One final point re: 300TDI cruise controls: make sure you regularly check the integrity of the rubber vacumn hoses that operate the system as they have a tendency to rot unexpected, resulting in some unexpected cruise control system activity when in operation.

tried cruise on my td5 you might be right but on british motorways it was a nightmare set it to stay in top gear and you end up stuck behind something,or having to break been driving thousands of miles for over twenty years even with reading road and other drivers it was a nightmare only use cruise in early hours with clear roads.

cruise on at about 57mph with horses in tow and i was spot on on the motorway, no issues at all.

towing with cc is achievable and comfortable

As soon as it hits a hill its down 2 gears and revving the arse out of its self. It wont stay in top gear and wait till the revs drop a bit , its like a 17 year old boy.
As I'am a hgv driver and drive every day in cruise I expected a bit better. But if I switch the cruise off and just go lite on the peddle it stay's in top gear for longger.

simon6949 said:

As soon as it hits a hill its down 2 gears and revving the arse out of its self. It wont stay in top gear and wait till the revs drop a bit , its like a 17 year old boy.
As I'am an hgv driver and drive every day in cruise I expected a bit better. But if I switch the cruise off and just go light on the pedal it stays in top gear for longer.

Click to expand...

Classic behaviour for a non-remapped TD5 auto using cruise control, when towing. It can also indicate a non-functioning MAF.

The problem arises due to a torque hole below 2200rpm, Torque Converter lock-up at 52-55mph and the use of Cruise Control.

A remap sorts out the torque hole and everything works 100% better as a result.


Dave