Re: Diesel acceleration query
Posted: Fri May 06, 2016 9:33 pm
Keep the revs at 1500 or above to avoid a torque curve that drops like a stone. Its good practice on all four cylinder engines, including petrol, anyway. The stable working range of high speed light engines usually spans from around rated maximum down to 1500. Below 1500, besides the torque curve issue, the engine becomes unstable under load and extreme stress is imposed on crankshafts. It may even hint at this in the driver's manual.
The other indication for this is the gear change indicator in the dash which will advise a down change when pulling hard under 1500.
Should you drive in this way, you will find near zero lag of any kind and you will be in the optimum torque range for acceleration. I find that it is very easy do drive most of the time with revs between 1500 and 3000, when I can easily achieve 55mpg and often 60. Town traffic does require lower revs quite often, but a steady foot and fairly gentle acceleration until 1500 makes all the difference. High revs are seldom required to drive a diesel quite quickly, but the K9K is quite lively. It does suffer from low start-off torque compared to many engines though, so it can be quite easy to stall from a standing start.
The other indication for this is the gear change indicator in the dash which will advise a down change when pulling hard under 1500.
Should you drive in this way, you will find near zero lag of any kind and you will be in the optimum torque range for acceleration. I find that it is very easy do drive most of the time with revs between 1500 and 3000, when I can easily achieve 55mpg and often 60. Town traffic does require lower revs quite often, but a steady foot and fairly gentle acceleration until 1500 makes all the difference. High revs are seldom required to drive a diesel quite quickly, but the K9K is quite lively. It does suffer from low start-off torque compared to many engines though, so it can be quite easy to stall from a standing start.