Peugeot 306 HDI 5 Door

[Toms306]

Yes, you'll use a small amount more to get over the wind resistance, but it just isn't 30% or anywhere near that even! If I got 30% better fuel economy at 60 than 80 I would do that, but its just not even noticeable, I never get a dropping average on the trip computer at a steady 80mph, it only drops when accelerating or using the engine cold. I lose more MPG on a 5 minute cold trip to Tesco than I do at 30 miles at 80!