As for mpg, just bear in mind if you are going by the mpg display that cars tend to have these days – well they lie to you. I suspect that it is the case across all or most car brands.
This is true, but it's not always the wrong way. My last Mazda claimed 65mpg but was actually around 60mpg. My current Kia claims 61, but is actually 64.
I tend to be more aware these days, not just for cost but for environmental reasons as well. I used to happily go from Perth to Torridon for a weekend, now it would have to be for a few days at least. Weekend trips have to be south of the Great Glen.
I did do a 3 day walk using the train recently. Took the train from Dunkeld to Blair Athol, then walked via the Minigaig and Kingussie to Dalwhinnie before getting the train back to Dunkeld. The train was £22.50 and I had to sit on the floor by the toilets as there were no seats. Not the best advert for public transport.