Hi all, I'm running Chevron supr.10/30 in my Ford 4.6L right now(in Arx rinse phase), and I'd like to keep using it also when it gets warmer, and in summer. For this, I really would like to thicken it up a bit...say somewhere around 12cSt@100 or so...somewhere between a 10/30 and a 10/40. What would be the best Chevron oil to use for this? Chevr.10/40? or Delo400 15/40?(those are the only Chevron products I can find in Walmart) What would be a good ratio to mix?(capacity with filter is 5.5 qts) Also, are there any other (dino)10/30 oils which offer better "thickening-up" or mixing possibilities? (..I can get Pennzoil dino 10/30, 10/40, 20/50 and LL-15/40 at Wally, also Pennz.HM 10/30 and 10/40) Any suggestions/ideas are thankfully welcome.