On 6 Aug, 13:53, Marlon wrote:
Hi all,
* * *having just swapped an automatic for a manual, I now have gears and
a tachometer as controllable variables in my driving.
* * *So it occured to me that I've never really done that bloke thing of
knowing about rev ranges, when "best" to change gear (other than when it
feels "right"), and such like.
* * *So.... for instance, given there's an obvious upper range to be
avoided (as indicated by red lines), is there actually a practical lower
limit (obviously without stalling)? *Is there a "sweet spot" in between?

As I understand it, which could very easily be wrong:

- You should avoid using low revs with high throtle, as this can
damage the engine, in particular cause the head gaskete to blow. I
interpret this as hardly touch the throtle with the revs lower than
1.5k, and do not use full throtle below around 2.2k.

- When accelerating, the engine works most efficently at full throtle
between 3 and 4k. If you want to save fuel, change up at 4k and that
is usually around 3k in the next gear.

- Engine damage occurs over about 0.5k over the red line. Unless
really critical, do not use the revs above this. Most modern cars
have rev limiters that prevent going much over the red line anyway.

This is all based on petrol cars. I know even less about tractors