Towing Gear and Fuel Economy

[Patchspal]

We recently bought a Land Rover Discovery 1997 which we love, but we have a couple of issues - one is we have been told to stay in 4th gear when towing the tri axle trailer but my husband insists that it is Ok to drive in 5th. We just had it converted to gas and after doing 145kms it took 44 litres of gas which seems high considering our brother in law got a lot more out of his vehicle, with a tractor on the triaxle. Can anyone give some extra weight to the gear selection and a clue as to what we should be getting in economy on lpg. Many thanks in anticipation, Patchspal.

[seano87]

4th gear is much stronger than 5th due to 4th being a straight 1:1 ratio, 5th has extra cogs as it is overdrive.

I very rarely use 5th when towing any considerable load (manual 300tdi) simply to avoid undue stress on the gearbox, and I have found I can actually get better economy as the engine doesn't have to labour as much to hold speeds, particularly up hills.

Can't help with what the economy should be, consider weight and drag through, and basing a consumption on 1 tank is generally not very accurate.

Seano

[slug_burner]

sounds like you have one of the V8 discos. can't help with the gas consumption but I would advocate the no using 5th advice. Only if on very flat easy going road would I slip it into fifth.

[TheLowRanger]

Best figures I've had with my 97 D1 V8 on LPG, whilst towing my roughly 1.8T off road van, have been about 29 L/100k's. This is roughly what you have gotten on yours.

[justinc]

The R380 gearbox is way stronger in 5th than most other 4x4's gearboxes, but I would still use 4th for towing/ heavy work. 5th is fine on the flat, but into a headwind or hills I'd slip back to 4th. Many have used 5th for towing regularly with little problems, but it is best to treat it as an overdrive if you want long life from the trans.

JC

[Patchspal]

Appreciate your help!

[Patchspal]

Many thanks for the advice , sounds like I may have more proof to back up a point of view!

[Patchspal]

Our brother in law got a whole lot better economy in his 96 model.

[dirtdawg]

44 lts of gas is only about 22 dollars so thats not too bad considering you were towing a half decent weight for 150ks, when i tow my camper which weight about a tonne fully loaded i get about 170 to 180 klms from 50 ltrs of gas

[buzz66]

Christ those 3.9 V8's use some fuel.

If I load all the camping gears half of it on a roof rack, 60 litres of fuel in jerry cans, tools, parts, hand winch ETC, wife and kids. The worst economy I get is 20L per 100 KM on the highway and that's sitting on 120KM on the flat, and revving the crap out of it in second & third gear on hills. I don't have gas, only ever 98 octane. That's with a 21 year old 3.5 V8 with 175,000 KM, the same lifters and cam. 2.5 inch system is the only performance upgrade.

Compared to how much I spend on keeping it on the road, the fuel used doesn't even get a look in. The amount I'm spending on the transfer case will keep my truck on the road as a daily driver for a year. :eek: