I've been driving locally for about a month and now today I am venturing further where I will be on a bypass for a large proportion of the journey where the speed could be 60 or 70 , ( relying on a sat nav!) locally only the moors has a highish speed limit of 50 for not very long and then I've kept in fourth gear. I've searched and searched online and found that people use 5th gear at 40, now I'm really confused as I doubt my car would as it does struggle in 4th gear at 30 on slopes