Motorway speed limits are usually 110kph. Some stretches will give you the option of 130kph when the weather is good restricted to 110kph when raining. Road signs, roundabouts, junctions and traffic lights are different in France. The AA and RAC have good packs for continental travel and these are worth having.
French people do drive differently from us in the UK. Motorway traffic seems to pay little attention to the speed limits and 120kph is not at all uncommon. Two things to avoid are do not try to ‘poodle along at 60mph/90kph in the inside lane on three lane motorways and don’t expect to drive, as many do in the UK, by doing a ‘steady 70/80mph 110/130kph in the middle lane’. If you do either of these two things you can expect to be on the receiving end of considerable irritation and much abuse!
You will also need to use your rear view mirror a lot more than in the UK due to the high speeds of traffic coming up from behind. One final tip, the French do not pull out early and spend a lot of time overtaking – typically they get very close, signal and pull out as one manoeuvre – the sort of thing that would attract much abuse in the UK is common driving technique in France as is leaving the indicator going when overtaking a long queue of traffic.
Nearly all French service stations sell super unleaded 98 (sans plombe 98), ordinary unleaded (sans plombe 95) and diesel (gazole). Prices are generally cheaper than in the UK and are usually cheaper still off the motorways.