Fuel Economy and "Short Shifting"...10% saving.

gday guys

a couple of ways to save fuel while driving...........

1. keep engine revs to a minimum ( up to around 1800 rpm,depending on engine size etc)
2. when driving down hill take your foot off the load pedal,allow the vehicle to coast downhill.
3. short shift when not towing or going downhill.
4.remove excess weight when items not in use ( jack,recovery gear etc)
some of these methods we use in the transport industry & they work.cheers.

Must say that I agree 100%, although I can't remember what it was like to drive a petrol powered 4x4.....but don't reckon those sorts of revs were needed.

With the big 6.5 Chev V8 diesel, I feel as though I'm over revving it if I go past 2000 !!!!!! hahaha

Most change gears at around 1400 to 1600 and only get to 2000 when I'm at highway speed.

LOL you old farts have been driving tractors engines for too long. Seen 6500 briefly in a work Commodore while passing a semi , and that was letting the tranny do its own thing.
Seriously 4000rpm in a dohc v6 equates to about 2000rpm in a diesel. The only time I rev the Jack is passing semis etc in third where it will easily wind out to 120ks which is still 1500prm away from the redline. I presume Jims v6 is also dohc at 4000 prm he would just be entering his max power ban.
Cheers Pete

Old Farts LOL.

That's me too. I can remember my FC with the "Grey" motor would start to valve bounce at 4500 rpm. Petrol motors have progressed a bit since then.

Goodmorning Jim,
Those where the days. I spent plenty of time on the redline when I was a young bloke. Those old motors(gret and reds) where not really ment to have large lumpy cams . I use to get on average two years out of a rebuilt motor, gearboxs less. Have not rebuilt a motor or gearbox now since about 1980. Mine you the last red motor I had rebuilt(blueprinted and balanced) with a yella terra head cost a bit over a grand.Hate to think what the Jack would cost.
Cheers Pete

Hey Pete,

Get this. My Uncle had an FJ in the early 60's that had a Grey, with a Repco Cross Flow Head, Triple Webers, Extractors, Compression Ratio Upped, Flywheel Lightened etc.

It was dyno'd and was producing over 160 HP at the back wheels.

He used to take it down to the Drags ang it quartered in 15.9. That is still quite respectable for a modern performance car.

Jim.

That would have been just about full race spec then Jim. Heard plenty about the fabled repco cross flow but never seen one. Never seen a grey with triple webbers either, most common was twin strommies or triple strommies or triple sus. I had my fc when I was 17, and had no money, could not even afford decent radials.lol
Had a mate who was a bit like the fonz but before that show who had a couple of nice fjs.
Mind you the donk in the Jack produces a l ot more power then the mildy worked 253 I had in my SLR, the Jack just weighes an extra 800 kg
Cheers Pete

I've actually got some under bonnet photos of it on "slides" somewhere. It was something to look at I can tell you.

My Grandfather was a very good Automotive Engineer and he was for ever fiiddling with the Webers after one of Geoff's know all mates bleep ed with them.

It used to rev to 7000. The greys had an harmonic vibration problem at 6400 due to the 4 bearing crankshaft.

Jim.

Gee that was a lot of revs for a motor that was designed 70 years ago. Must have had a full race cam to do that. Cannot remember the specs now but 35/75 I think was 3/4. I mostly used 25/65 nice mild cam. Had one 3/4 which was a pig, had to be doing 70mph to get it on cam, bit hard towing a boat.lol, Thirsty as hell as well.Last motor I built in my childhood was a mild but lovelly motor. Blueprint and bal, yella terra head, bored to 190ci standard cam and a mate adapted a webber off a cortina(I think) for me and extractors, by this time I had torque more in mind.
Had a repco with too high a compression ratio, had to retard it 18 deegrees to run it on super, use to run on. with a 3.55 ratio diff was nearly as fast up conrod as coming down.
You have got me remembering all the old times now Jim. Good night mate.
Cheers Pete

Pete,

He spent a bloody fortune on it. My Old Man said he just pumped everything he had into. A bottomless pit.

Clutch was obvious weak point. He used to carry a spare in the boot and did so many that he was able to drive it up onto the kerb and change it under an hour.

Jim.

Best I done a clutch in was an hour and half. But their where vsimple cars.
I let my mechanic do itt all now Jim, works out cheaper.LOL
Cheers Pete