Improving MPG.
Discussion
I know... owning a TVR and MPG don't go hand in hand, but with the cost of fuel going up so much I was wondering what could be done to help improve the MPG. Alot of the time my driving is above 50mph.
1 Change diff ratio. This would affect performance in all gears.
2 6 Speed gear box. Cost prohibitive, would one fit.
3 Higher 5th gear. Wouldn't affect performance in 1-4th but when motorway crusing in 5th would improve mpg.
Anyone got any views.
1 Change diff ratio. This would affect performance in all gears.
2 6 Speed gear box. Cost prohibitive, would one fit.
3 Higher 5th gear. Wouldn't affect performance in 1-4th but when motorway crusing in 5th would improve mpg.
Anyone got any views.
A fair question as I guess we've not all got bottomless pockets but still love to have the cars. My thought's (as a Tresspassing Cerb owner) ; keep it well serviced. A good dose of Redex\Wynns every couple of weeks . Perhaps some Molyslip at oil change. Dunno if that helps but it's all I can think of as a layman to the mechanical world. 
Pink_Floyd said:
I know... owning a TVR and MPG don't go hand in hand, but with the cost of fuel going up so much I was wondering what could be done to help improve the MPG. Alot of the time my driving is above 50mph.
1 Change diff ratio. This would affect performance in all gears.
2 6 Speed gear box. Cost prohibitive, would one fit.
3 Higher 5th gear. Wouldn't affect performance in 1-4th but when motorway crusing in 5th would improve mpg.
Anyone got any views.
You've got to be realistic on your ROI when looking at these options. For the meagre improvements in MPG your initial outlay will take a long while to repay itself and at what cost to the drivability? Just enjoy it and try not to think about the cost every time you press the loud pedal... That's my approach anyway! 1 Change diff ratio. This would affect performance in all gears.
2 6 Speed gear box. Cost prohibitive, would one fit.
3 Higher 5th gear. Wouldn't affect performance in 1-4th but when motorway crusing in 5th would improve mpg.
Anyone got any views.
In general I agree with the above but clearly it depends whether you think you have a problem. What sort of figures do you get? (you dont say). If you do have concerns that the consumption is abnormal then get it looked at.
With my 450 the brim to brim figures vary from around 12mpg to 26mpg depending whether its stop / start blasting and overtaking or motorway cruising in light traffic below 3 digit speeds. Even with the ultimate in fuelling efficiency, use of friction modifiers, high tyre pressures, keeping the roof on, polishing it etc, you arent going to gain more than the odd 1-2 mpg. Mostly its down to your right foot.
Achieving excellent fuel efficiency isnt the reason I drive the TVR (or anything really TBH) I drive it for the thrill of its dynamics, the sound, and the whole visceral experience of a hard-core sports car.
With my 450 the brim to brim figures vary from around 12mpg to 26mpg depending whether its stop / start blasting and overtaking or motorway cruising in light traffic below 3 digit speeds. Even with the ultimate in fuelling efficiency, use of friction modifiers, high tyre pressures, keeping the roof on, polishing it etc, you arent going to gain more than the odd 1-2 mpg. Mostly its down to your right foot.
Achieving excellent fuel efficiency isnt the reason I drive the TVR (or anything really TBH) I drive it for the thrill of its dynamics, the sound, and the whole visceral experience of a hard-core sports car.
At the moment I have the car totally in bits for a chasis referb, so whilst its apart it would be easy to to make any mods. My 4.0 use to give 16mpg running around and 26 on a long run, so not bad. I to have the car for the sound, the performance and the drivability, so was just wondering what my options COULD be for improving long distance runs.
You could go back to the Range Rover fuel map, it uses less fuel, but you loose about 12 bhp (on a 4 ltr) in the process, and you will find a rev limit at around 5400 rpm. It does run somewhat leaner at the higher RPM, that some say can damage the engine. Ive personally not come across any engines damaged this way so I dont know how much of this is scare mongering by the re chipping companies. I would think some of the engine rebuilders could advise better on this one. Its unlikely to make any odds at the lower end of the rev range. Mark Adams is you best bet on accurate fuel mapping.
Mark
Mark
Want to improve MPG?
Don't drive with the roof off or the windows down. Driving with the roof off is a big MPG killer.
Take everything out of the boot that you don't need including the useless space saver.
Increase the tyre pressures but don't push the car as the handling will suffer badly.
Drive smoothly and anticipate everything so that there is no harsh braking or acceleration.
Keep the speed down to around 55 ish when cruising.
Block off the rad in winter to ensure the car runs at 80-90.
A six speed won't fit.
Changing the diff ratio is a possibility but will trade in gear acceleration for lower revs at top speed. With the limited power the 4l has... not a good idea.
Payback for these is a long time.
Don't drive with the roof off or the windows down. Driving with the roof off is a big MPG killer.
Take everything out of the boot that you don't need including the useless space saver.
Increase the tyre pressures but don't push the car as the handling will suffer badly.
Drive smoothly and anticipate everything so that there is no harsh braking or acceleration.
Keep the speed down to around 55 ish when cruising.
Block off the rad in winter to ensure the car runs at 80-90.
A six speed won't fit.
Changing the diff ratio is a possibility but will trade in gear acceleration for lower revs at top speed. With the limited power the 4l has... not a good idea.
Payback for these is a long time.
Fit an aftermarket ECU.
Some have the ability to turn the fuel injectors off whenever the throttle opening is below and rpm is above a set figure. You set the figures.
Then whenever the car is on the over-run you're using no petrol at all.
AFAIK the Lucas can't do this.
In addition the improved efficiency of mapping the ignition and fueling together should provide more power and economy.
Unfortunately this isn't cheap to do, so will take quite a time to pay for itself.
Some have the ability to turn the fuel injectors off whenever the throttle opening is below and rpm is above a set figure. You set the figures.
Then whenever the car is on the over-run you're using no petrol at all.
AFAIK the Lucas can't do this.
In addition the improved efficiency of mapping the ignition and fueling together should provide more power and economy.
Unfortunately this isn't cheap to do, so will take quite a time to pay for itself.
Timja said:
dougc said:
Spend £750 on a diesel 306 snotter.
I have just started looking into this! - Getting expensive to drive the TVR everyday, so I think i could save about £25 a week in fuel buy buying a 2nd car - Will pay for itself over a year! (Assuming there are no big Peugeot bills!!)Gassing Station | Chimaera | Top of Page | What's New | My Stuff