Re: runs poorly when hot
If the engine is knocking under load - I would advise against giving it any more fuel or you'll have more problems on your hands. Still, even if the plugs aren't all that old (say two years with lower miles), pull one or two out and make sure they look OK (not burnt/electrode missing, etc). If the fuel system checks out OK, get a compression test done.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!