Low term use of Low range while towing?

[crazydave]

Long term use of low range while towing?

I have a boat that I want to tow occasionally (4-5 times a year) with a 07 N/A manual DR. Boat weighs about 1200kg- 1300kg so is legal but near max weight for the car.

At 100km/h in 5 gear the engine is about 2500rpm. I have to change down to go up a gentle rise even at WOT so the engine is not happy with the load at this rpm. In 4th gear at 100km/h the motor is at 3500rpm goes up hills fine but is on the noisy side for a long drive and drinking the juice.


The motor seems to be happy at about 3000rpm (for a motor lugging a bloody great boat around) has some reserve to get up the hills, reasonable noise levels and doesn’t drink the juice so much.



So the question is can I tow in 5th low range at about 3000rpm about 95-100km/h- the manual says you can at that speed but is not clear on how long for. My main concern is the low range gearset is high in the gearbox and I am concerned about it getting enough lubrication on a long drive.


Has anyone had any experience of the LR gearset wearing? Should I overfill the gearbox if I want drive for extended periods ie 200-400KM on LR?



Crazy

 

[Venom]

Oil starvation of the low range problems are more of an extreme offroad thing. Going up very steep, long/slow inclines where the oil drains to the back of the gearbox.

Low range should be getting plenty of oil on anything other than a very steep incline, the sort of thing you're very unlikely to be doing with a boat on the back.

 

[taza]

Yep that should be fine mate, if it's really steep go back to fourth as fifth gear is your overdrive gear and 3 tonne of pressure on it while straining the engine could break your gearbox. My Forester has remained in low range for the past 10,000km onroad due to a tied engine producing half of it's standard power. The use of the lower gearing has allowed me to just keep up with day to day city traffic and take off on hills without it feeling like your trying to use 3rd gear. So far no damage has been done to the box.
What do you call bad fuel consumption while towing? I'm curious as I am going from a 2.0l to a 2.5l in my 2001 Forester and am curious for when towing.

Best of luck mate.

 

[Ratbag]

Gidday Dave

Owners manual recommends not to exceed 188k/h in 5th LR while towing all day ...

From my Batphone

 

[crazydave]

Thanks folks, Sounds like it will be ok.

Taza haven't towed Tubby (the 1300kg powerboat ) yet, but did tow a hobie 16 to Gero over the March long weekend. 3 up with gear and tools, trailer is heavy so probably all up 500kg but 2.49m wide so has a lot of windage.

Towed at either 3500+rpm in 4th or 3000 in 5th and sitting on 120 (bit fast) it used about 13l per 100km either way.

FYI I normally get 8.7-9l/100km commuting 20km local trafic 28km freeway against traffic.