Thread: Fuel consumption

Originally Posted by 001525

Mate, I couldn't give a rat's bum about all this mathematical mumbo jumbo. I'm only interested in the bloody truck starting and getting me to where I want to and back again without a break down. I thought it was common knowledge that the faster you go, the more fuel you use. The slower, the less fuel. This is irrespective if you're driving a European V12 or 1 litre Japanese soap box.

resist what? is your husband away and you need to let it all out?

Hey it is an interesting thought process, must say I rarely drive for economy, except when travelling with friends who have Patrol's..... BUT that is for their economy, doesn't make enough difference in the Disco for me to worry about the extra time it takes on a longer trip usually.

i think aircraft would have to use a similiar formulae...
anyone know?

I almost always drive for economy, I travel early in the morning and late into the evening to take maximum advantage of the cooler air and that people generally travel more slowly at those times in fear of roos and the like.

theres a couple of rough rules i use to work out which is the most economical speed excluding doing actual test runs..

1. grab hold of the power/torque chart for the engine and look for the point where the peak of the torque curve is, then overlay that on the predicted fuel consumption graph for the engine run against a full load where the torque curve is relatively high for the fuel consumed thats where the engine is running near its optimal effeciency. Take that RPM number and crunch it down through all the gear ratios required to get to the actual turns of the wheel. Multiply the wheel RPM for the given engine speed by the circumfrence of the wheel in cms then multiply by 60 and devide by 100000 to get your speed in KPH. now in an ideal world thats the most effecient speed you can run your vehicle..

2. look at the speedo in all but one of the cars IVe owned in the past when the speedo needle was vertical on the gauge then it was driving at peak effeciency...

Originally Posted by Blknight.aus

2. look at the speedo in all but one of the cars IVe owned in the past when the speedo needle was vertical on the gauge then it was driving at peak effeciency...

I was going to mention the above point. Someone told me about the vertical needle on the speedo trick in the mid '70's.

I have found it to be correct. Until they buggered it with those digital speedos.

Now where did I leave those budgie smugglers ?

Hadn't heard the speedo one before.... Or is someone trying to lead me up the garden path???????

Originally Posted by cookiesa

Hadn't heard the speedo one before.... Or is someone trying to lead me up the garden path???????

It proved true on our XY Falcon, XB V8 Fairmont, XD Falcon, RV Tarago, Mitsubishi Galant, Ford Meteor, and all of our Land Rovers.

OK I'll believe it then... Have a highway run coming up so might give it a go