Speed in 4th td5 discovery

[disco_potato]

What is a safe speed to sit on in 4th gear with a td5 disco 5 speed
I tow my race car regularly and I have heard it is not a good idea to use 5th gear for towing. 100 kmh in 4th is around 3000rpm is that safe?

[MarknDeb]

read the cars manual to see what it says RE towing speed and gears, if it says nothing you are able to do the speed limit in 5th

[disco_potato]

Thanx. I didn't think of that.

[Tombie]

I'd be towing on the flat in 5th...

And then dropping back on inclines :)

[Disco Muppet]

^ X2.
Don't keep it in 5th under ANY strain.

[Alex 110]

drive by your egt's. Others may correct me but my understanding is they will be lower with more revs in a lower gear (within reason) for any given speed - especially under load

[BigJon]

drive by your egt's. Others may correct me but my understanding is they will be lower with more revs in a lower gear (within reason) for any given speed - especially under load

I think the concern is gearbox strength rather than engine EGT.

[Blknight.aus]

depends on the weight your pulling and the general conditions. (wind, roof rack, surface conditions)

I'll back tombies advice on this one.

[robbotd5]

EGT's have a great way of telling you how hard your engine is working and henceforth how much strain is on your box. I tow a 2300kg van and while I use 5th, it has to be under the right conditions, ie, flat road, minimal headwind cool ambient ect. I try to not pull any more than 15psi boost whilst in 5th and under these conditions I can maintain the magic 90-95.
Ideally, 4th is the go but the revs do get a bit tedious at times. Mechanical sympathy is the rule of this subject.
Regards
Robbo

[Yorkie]

4th and 3000rpm gets annoying so I use 5th on the flats bits and downhill keeping egt's under 500'C.

[disco_potato]

Thanx for the input guys. That is one down fall on the disco compared to my old gu patrol with the rd28t. The patrol could cruise all day in 4th at 100 kmh but it had to because it was guttles compared to the disco.