Fuel economy of 3.0litre TD RWD vs AWD

I have read some of the posts re fuel economy but I haven't found the info I'm looking for.

I have read that the AWD 3.0litre TD is thirstier than the RWD version due to presumerably the extra weight of the 4WD components. Any thoughts on how much thirstier it would be under similar driving conditions here in Australia?

I already know that my running costs will be higher than for my Toyota 4Runner2.8L non turbo diesel, which gets around 10 l/100km (occ sneaking in less than that). Also the SC uses 7(?) litres of oil during oil changes as opposed to 5 for my current vehicle.

Just doing my homework, that's all!!

uknown refuel economy but my 3lt turbo uses no oil between services i normally get around 500 to 550 k's per tank of fuel hope this helps

On my recent highway run (some city driving but mainly country) covering in excess of 3000km, I got a fuel average of 10.17 l/100k. I am driving a 3 litre rear wheel drive SC, 2 people plus gear on board, not towing a trailer. I realise this is not the comparison you are looking for but it might help somebody.

In November, I'll be going on a lengthy trip away with more or less the same setup as you've got, Spanner i.e. 2 people + gear, no trailer, the main difference is that my van is 4WD.

Based on the limited highway driving I have done so far, I am anticipating an average fuel consumption of between 12 & 13 L/100km for the trip. Will post results in December when I return.

wernerk,
Bear in mind that the AWD system on the later SCs uses a viscous coupling instead of a transfer case. This will impact fuel economy as a result of the losses in the coupling as well as the extra weight, both static (ie the van is heavier overall) and dynamic- the extra parts (front diff, coupling, driveshafts) need to be spun up and/or slowed down every time your speed changes.
With the RWD setup you only have the wheels+brakes themselves plus the rear half-shafts/diff/driveshaft that rotate, so there are lower losses. With the P/T 4WD you get the static mass but can disconnect the front section of the transmission between the transfer case and the front hubs, so that alleviates the loss much of the time.

Sorry, I can't quantify this... I suspect that the impact is quite low (ie less effect than a heavy right foot or substantial load), but constant ('cos you can't remove it or change your driving style)... if anyone has better info (or disagrees with the above :-) I'd be interested to hear!!!

Cheers,
W.

W,

I agree with what you have said and although I can't change the transmission components which contribute to extra fuel use, I can change what I do have control over to improve fuel economy e.g. remove excess weight, change driving habits, increase tyre pressures (once I replace the tyres) etc.

In the ideal world, my van would have 5 speed manual transmission with part-time dual range 4WD , but unfortunately we live in the real world

Werner

Hi Werner,

I get about 6.5km/l in mine around town and up to 8.5km/l on the highway. This is about 15l/100km and 12l/100km respectively. Towing the caravan on the highway I get around 7.5km/l or 13l/100km. The all up weight including the caravan and a full vehicle is about 4.5 tonnes so this isn't so bad.

Cheers,

Dave