Is 5W-30 suitable for summer conditions? I put some in last week, and it seems to be doing fine, and the owner's manual recommends it...


1999 Ford Mondeo 2.0 Aspen 1997 Opel Astra 160iE "Squish" R.I.P. 1980 Jaguar XJ6 4.2 Series II R.I.P.