i used to think red was the same just with a dye in it. my mate had an old bmw 325tds that used to love it and ran on it all the time. he swapped that eventually for a newer 320d e46 and that didn't like it at all, wouldn't run right so he drained it and put white in and it was fine. he was quite pissed off because up to that point he'd not been to a petrol station for about 3 years!