Diesels, Red Lines,
I need to take my medication.

Every diesel I've ever had emits a cloud when you give it the beans, even the ones that you drove hard all the time, you see it more at night as the particles seems to show up more in the headlamp beams of the car behind you. Geoff

If you stick your foot to the floor in a td6 or other auto diesel it will always change up before the red line is near

Now you could over rule this by sticking it in low range but I wouldn't risk it
Also the command shift will change up before the red line as well.

An MOT tester should give the engine some revs, usually to clear it out a little but hut also to make sure it's not overly smoking as part of the test is a Smoke Test so they need to test it and the only way while stationary is to give it some hoof

This is all my opinion by the way so if some don't agree that's there choice, but in my years of bio and veg use in diesels I've never had one smoke during my ownership other than on the day i picked them up  FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.