About 70 mph - judging by the Irish HGVs on the A75 to/from Stranraer and the Polish HGVs on the M25 to/from the Channel.

More gears don't particularly help, now they have plenty - it's their power-to-weight ratio that limits them going up hills.

That makes sense, thanks

This is currently being discussed in the "A14 driving etiquette" thread. Would you like to join that discussion, or we'll get two threads on the same topic.

Edited by Avant on 04/12/2013 at 17:44

I had a MAN artic in late 80's that would cruise at 95 if you so wished, and i don't mean kph.

Most properly specified lorries (especially Cummins engined with the right gearing) of that era would run up to about 80, Swedish stuff ran out of puff long before that, not geared so well.

The legal motorway speed limit for LGV's (over 7.5 maximum laden weight) is 60 mph, but by law they have to be fitted with a speed limiter set at 56 mph.

On dual carriageways the legal speed limit for LGV's is 50 mph, and on single carriagways it's 40 mph.

https://www.gov.uk/speed-limits

The limiter only affects the throttle, not the brakes, so LGVs can/do accelerate legally up from 56 mph downhill - in these circumstances they can legally do 60 mph on motorways and even going up to 67 mph is still within ACPO guidelines