As many as 88 per cent of those behind the wheel in firms' vehicles regularly exceed the limit compared with 67 per cent of private motorists.
Also, 62 per cent of company car drivers said they reached speeds of 80mph on motorways, almost double that of regular motorists (32 per cent).
In addition, eight per cent of company car drivers hit 90mph or more, compared with three per cent of private motorists.
When asked why they broke the speed limit, 31 per cent of company car drivers said they were just following the general flow of traffic, while 19 per cent put it down to the driving conditions being favourable. But 15 per cent said 70mph felt too slow.