improving mpg ,not using 6th?

[mrk]

read a few comments on here about mpg increasing by not using 6th gear,i assumed 6th gear reduced revs there by using less fuel.any thoughts or experiences of mpg increases welcome

[Das]

I understand the theory. If the engine is labouring in 6th it will use more fuel, therefore 5th would be the better gear to be in.

[marc vectra sri]

so if am cruising at 70 in 6th it using more fuel than being in 5th using more revs how does that work

[nikroc]

I would have thought that if your motoring along at 70 then the engine wouldnt be 'labouring'..6 th at that speed drops my 2t to APPROX 3k revs..

[rockafella8587]

If you are doing maybe 50mph then that is too slow for 6th gear to be efficent, so 5th would be more economical as the engine would not be labouring. But motorway speeds then 6th will be the optimal gear. So maybe the 5th gear tip is most suited to a and b roads. I have noticed this is true and I alway try to match my gears to my speed so the engine doesnt labour. Just play around and you will get a feel for it

[Greebo]

under 70 i use 5th if i go to 70+ then 6th is used, i found that the engine labours just that bit more in 6th than 5th at 60

[Rebellion]

Apparently the engine is operating most efficiently at the point of maximum torque (torque, rather than BHP). if true, then obviously the RPM at which 6th is more efficient than 5th depends on which engine you have, so refer to a torque graph for your engine and see where torque reaches its peak.

[Das]

Apparently the engine is operating most efficiently at the point of maximum torque