I personally don't think it makes much difference, especially in an emergency. And I use 20/50. And always carry at least one spare valve cover gasket. --- On Fri, 3/6/09, Brian Denning <i_am_cool_fred@xxxxxxxxxxx> wrote: From: Brian Denning <i_am_cool_fred@xxxxxxxxxxx> Subject: [tcb] not your usual oil topic To: tcb@xxxxxxxxxxxxx Date: Friday, March 6, 2009, 5:04 PM #yiv774784130 .hmmessage P { margin:0px;padding:0px;} #yiv774784130 { font-size:10pt;font-family:Verdana;} ok, so i was running those crappy chrome valve covers...was is the key, i hit a bump and it sucked in a valve cover gasket. so i pull over call a friend who has one with him, he brings it, i evidently leaked out a bit more than i thought..i was a good quart low, he says here put this in. it was 40 weight. i use 30 weight so i said, it'll make it home (about 2 miles) he said, i've always mixed and haven't had any problems. i've always heard you can't mix...can you? 30vs40? is it really going to hurt to mix a bit of 30 with the 40? it's 80 outside right now. does that matter? Express your personality in color! Preview and select themes for Hotmail®. See how.