4th or 5th gear towing

All depends what speed you want to sit on.....

Most of the road is flat, so at a speed of 100K's , 5th would be best ( and quietest )

What revs is it doing at 100K's in 5th and also in 4th ??

Have a look at your torque charts for your model and see what revs it is in. Then put your gear to suit. Also no harm in working out some actual figures. My guess though for a petrol would be to tow in 4th as the max torque tends to be quite high relatively speaking.

If towing a camper weighting in at 1.5 ton don't think i would be using 5th gear at all. There's not a great deal of difference in fuel consumption between 4th and 5th gear anyway.
Cheers
Baz

Depends on what diffs you have, our old nh Paj was so low geared 5th was the same revs as 4th in the Jack at 100. 100 is very comfortable in fouth in the Jack but not the Paj.
Cheers Pete

Depends on what diffs you have, our old nh Paj was so low geared 5th was the same revs as 4th in the Jack at 100. 100 is very comfortable in fouth in the Jack but not the Paj.
Cheers Pete

Everyone above is correct but can I add that the absolute best way to maximise your fuel economy is to fit a good old vacuum gauge.
Ideally you would tow at the rpm at which the engine develops maximum torque but you also have to balance that with wind resistance and therefore engine load hence the vacuum gauge.
For example you may well be able to tow at 100kph in 5th gear quite happily with the engine at max. torque but even with a really torquey engine you will very likely find that you could reduce the speed a little and tow in 4th gear with the throttle backed off. This will substantially improve your fuel economy because the engine is not working as hard.
With the gauge you basically just balance road speed, engine revs with maximum manifold vacuum.
We use a version of the vacuum gauge in both turbo and non turbo piston engined aircraft and use it in just this way to maximise range and endurance.

Also if your 5th gear is an overdrive gear ie less than 1:1 you are reducing the available torque applied to the tailshaft compared to a 1:1 4th gear and therefore by definition the engine is working harder.
This subject is not quite as easy as it sounds but I hope this helps.

I'll just say that I towed my 2.5T Roadstar with my petrol/gas prado V6 to Esperance and back to Perth in 5th gear and now I have some play in my drive train (read transmission). When I stop and restart I get a noticeable clunk in the transmission. Not serious (I hope) but a concern nonetheless given I leave on Sunday to do half a lap and 21,000KM. Mechanic said not to worry but gave no guarantees I wouldn't have problems down the track. 4th gear for me from now on.

For best economy sit on 80 to 90km/hr in 5th.
Back to 4th for any hills.
Otherwise drive as you would normally for economy by being very light on the throttle. :o0
My figures towing our CT are 11l/100k at 80km/hr, 12 to 13 at 90 to 100k, 14 to 15l/100k at 110k, so speed and wind resistance has a lot to do with it. Add another 1 to 2/100k for hilly country and again for head winds.

Have a good trip.

I towed a small 1300kg pop top camper with a Toyota Troopy in 5th gear ... between 90 and 100 kph and never under load without changing down to 4th ... Toyota tough .. yeah .. replaced the gearbox .. and now use only 4th .. with better fuel economy ...

Hot off the press.We are currently touring for three months and I have observed the following towing our Tambo Cooper with 1HZ with turbo and I/C.
Towing in forth at 85kph 2500rpm I get EGTs around 300deg C post turbo
Towing in 5th at 95-100kph 2200rpm I get EGTs around 350degC post turbo.
I now tow in 4th