I went back to SA on the weekend from Canberra, the car return 9.33 litres to the 100 or 30 mpg over 2500kms. I'm still not impressed with the fuel economy the car it is an el 5 speed maunual futura running with a 3.23 diff, pacemakers headers fitted.
The car does 2000 rpm in fifth at 100 km/h. What rev's would it do at 100 km/h if I went for the auto 3.08 diff and what kind of fuel ecomony benefit would I gain? Am I chasing very dimishining returns? could I consider going lower than 3.08 maybe a 2.9 diff ratio, does one exist?
any other advice on how to improve fuel economy appreciated, would like to get 35mpg from at highway speed.
If your doing 2000rpm at 100km/h with a 3.23 ratio, you
will be doing 1907rpm at 100km/h with a 3.08 ratio.
OR be doing 1796rpm at 100km/h with a 2.90 ratio (if it exists).
Each of the above steps is approximately a 5% change. In a perfect world fuel economy would improve accordingly.
That is 9.33l/100km to ~8.9l/100km (3.08 ratio) to ~8.4l/100km (2.9 ratio).
In imperial from 30mpg to ~31.5mpg to ~33.4mpg.
All theoretically of course, ignoring all other associated factors.
Wowzers ! 9.33 L/100kms !! You've already beaten me hands down mate! I get *attrocious* economy in my EL wagon - trip computer says 14.5 L/100kms, but it's on gas too, and in reality I get about 20 L/100kms (something's not right atm). I would be damn happy with that kind of economy especially in an I6, presuming that is what you drive ??
Yes it is an I6, while it is good I would like to improve it further. My consumpution rate goes up when I have the bike rack on the rear with my bike by a litre a 100. My not on gas, can't afford to loss the boat space.
The type of driving I'm doing I reckon i could have the engine reving at 1500 rpm in 5th at 100 and still have enough power.
Did the xf come out with a 2.77 diff and would it fit?
My suggestion for better consumption at high speeds.
Go down to the wreckers and pick up an EAI 2.77. The LSD should cost around $150.
Better still, he would probably be more then happy to do a clean swap for yours.
Grab the controll arms as well.
Bolt it up to your car, and you will have some seriously low revs.
__________________ CAUTION: Slippery When BOOSTING!
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Linear Mode
