Dave Arquati wrote:

Unfortunately (for SWT) the 250-mile round trip will only cost about £25
of petrol by car in the small vehicle the OP mentions. I know that
doesn't include wear-and-tear, but as much as I like to promote the use
of the train, the car is almost certainly going to be more economical.

And, with 5 passengers in a small car with a small engine, quite
possibly just as environmentally-friendly.

Neil