1996 Chrysler LHS 3.5L SOHC V6 153,000 miles Engine has never been opened up but there is a reasonable amount of varnish seen when looking through the oil fill hole on the valve cover. I don't think I have any sludge problems but just a good amount of varnish. Anyway the manual recommends 5W-30 below 32F and 10W-30 between 0F - 100F+ which is my operating range. I just put in Valvoline All Climate 10W-30 and a SuperTech oil filter. I would like to use a good dino oil that doesn't shear a whole lot that also has a very good detergent and anti-wear package. Any suggestions for what brand and weight I should be using? Would a good dino 10W-40 be a good choice for this mileage engine? Thanks everyone.