Thread: More Towing Fuel Economy with the 2.7L

Have fun!

The hilly stretch of road north of the Kalbarri turn off I find tests the 2.7/6 speed when towing and I only tow a small centre console boat of less than 1.5 tonne. That weight is like a parachute on the way up hill.

Constantly clicking into top gear on the way down and dropping back on the way up over and over. It’s where Sport Mode or locking in 5th makes a big difference.

Originally Posted by gavinwibrow

So will be backing off a little and enjoying the scenery at 80 - 90 initially.
the real economy killer is air resistance increasing exponentially above 80.

Try driving even faster and see what happens.

My brother has a 3 litre HiLux with a instantaneous fuel consumption readout and tows a Jayco Expander. Like most people he found that as he goes faster fuel consumption goes up exponentially - but found something interesting - above 110kph (when he was able) fuel consumption started improving and if he managed to get to 120kph fuel consumption was even better than at 80kph.

His logic, which seems logical is that below 110kph there are two bow waves, one from the tow vehicle and then one from the unaerodynamic caravan sticking out above the car bow wave and creating its own. It would seem that above 110kph the bow wave from the tow vehicle gets so high that the second from the van is not created as the caravan is now slipstreaming in the bow wave of the vehicle. A bit like the drag od a boat before and after it gets up on the plane.

The trouble is the Hilux does not have the power to get up to 110kph towing except in ideal circumstances like dead flat and no wind or a tail wind. Sydney to Darwin and back he averaged about 17km/100 which is not too bad.

Garry

My ex-3.0 D4 (not towing) used less fuel cruising at 115 than 110 which I suspected was due to EGR operational at the slightly slower speed on such light throttle.

My 4.4 TDV8 uses less fuel towing my tall 2.5T van at 110 than 100 because the gearing is so high that 7th is used most of the time at 100 but 8th a lot of the time at 110 at around 1350 rpm. The over-size tyres don't help.

Originally Posted by 101RRS

Try driving even faster and see what happens.

My brother has a 3 litre HiLux with a instantaneous fuel consumption readout and tows a Jayco Expander. Like most people he found that as he goes faster fuel consumption goes up exponentially - but found something interesting - above 110kph (when he was able) fuel consumption started improving and if he managed to get to 120kph fuel consumption was even better than at 80kph.

His logic, which seems logical is that below 110kph there are two bow waves, one from the tow vehicle and then one from the unaerodynamic caravan sticking out above the car bow wave and creating its own. It would seem that above 110kph the bow wave from the tow vehicle gets so high that the second from the van is not created as the caravan is now slipstreaming in the bow wave of the vehicle. A bit like the drag od a boat before and after it gets up on the plane.

The trouble is the Hilux does not have the power to get up to 110kph towing except in ideal circumstances like dead flat and no wind or a tail wind. Sydney to Darwin and back he averaged about 17km/100 which is not too bad.

Garry

Trouble with that theory in WA is @ 120 your 20km/h over the towing speed limit of 100km/h

Would it be possible to buy a solar panel (or a piece of marine ply) and mount it as a wind deflector to your roof rack. Of course I’m assuming you have one. You could buy everything at a hardware or get some handy person to make it quickly during your travels. Just an idea.

Originally Posted by John_D2

Would it be possible to buy a solar panel (or a piece of marine ply) and mount it as a wind deflector to your roof rack. Of course I’m assuming you have one. You could buy everything at a hardware or get some handy person to make it quickly during your travels. Just an idea.

The Old “van air splitters” don’t do squat.

It’s the unclean air coming off the side of the vehicle and smacking the van that’s the major issue..

Originally Posted by shanegtr

Trouble with that theory in WA is @ 120 your 20km/h over the towing speed limit of 100km/h

Yes but West Australia/ns is/are just plain weird

Originally Posted by 101RRS

Yes but West Australia/ns is/are just plain weird

We like to be different - no point being sheep like everyone else