FORD is poised to take a dramatic 4x4 turn upmarket with a plush and speedy new version of its top-selling Explorer. Company executives unveiled a 140mph prototype of a super off-roader called Tremor at this week's Detroit Motor Show - then dropped significant hints that the 4.6-litre model would soon be in production.

With a massive V8 engine under its bonnet, the Tremor has 380bhp on tap and scorches to 60mph from rest in under seven seconds. Unlike the Explorer, which has just gone on sale in Britain (Fleet News January 3), the Tremor has independent rear suspension from the Ford Thunderbird sportscar and uses 19-inch aluminium wheels.