Diesel vs. petrol Streetwise

I've been running a diesel Streetwise for 10 years and about 150,000 miles. What a great car! At some time in the near future I'll be looking for another Streetwise to replace her, but I can only find petrol versions here in France with sensible mileages. Although the power outputs aren't hugely different, what's the petrol like to drive in real traffic? Overtaking 50 - 70mph? Motorway cruising at 80mph (legal here!)? Obviously I won't get the 50mpg+ I get from the diesel, but I assume 40mpg+ will be OK? Any pointers welcome.

from the last news http://ift.tt/1lCqJcV

via IFTTT