optimum rev range (low end)?

[57mab57]

I have a 62 plate a3 2.0DTI (138) and was looking at the handbook, when i pick up some conflicting advice:
General driving - "Change down when the revs get below 1500".
But "DIS gear selection indicator" often conflicts this - e.g. driving along at 28 mph in 3rd DIS says go to 4th, but doing this this puts me down to 1200 revs, and therefore I should change down again, to raise the revs above 1500! Is it just an economy thing - does driving around at <1500 damage the engine, or does it just give poor acceleration?
Any thoughts?

 

[desertstorm]

I spend a lot of time at less than 1500 RPM but mine is a 3.0 tdi . Doesn't harm the engine at all . When I had my 1.9 TDI Passat used to find the best economy when driving in 30-40mph areas was around 13-1500 RPM .
Obviously if you want to accelerate quickly you change down a gear or two.

karl.

 

[Kalashnikov]

ill just add by saying its possible to cruise below 1500rpm in my 143 tdi .@ 30-35mph

i regularly use 5th.. but don't think its advised when you see hill coming up.

1) you'll risk stalling the engine

2) you'll look like an idiot

 

[bonifacy87]

In my 3.0tdi I always keep her between 1600 and 2100 around town. Rarely go on 4th. Going below that in my opinion is loosing control of a car. But like I said it's just me.

 

[57mab57]

Thanks for your comments, clearly it's a choice between economy and acceralation/safety, but the engine won't be damaged at low revs.

 

[Jimmy TDI]

The engine won't, but constantly labouring at low revs will wear your clutch out quicker.