Oil grades? We have a 1979 Newell with 6V92DD (non-turbo) with 105K miles. Althought the engine is superb - the oil pressure has always been lower than I would like to see - approx 15 @ idle and 35 at cruise. We use Mobil 40 Wt - 2 Questions - Would the Del Vac 1 Multivis cause the oil pressure to drop any lower? And, is there anyway to improve the oil pressure?
Oil grades - If you prefer a synthetic lube oil, Detroit Diesel recommends a Mobil straight 40 weight synthetic marketed by Mobil under the Mobilguard SHC 1 brand name. We stock it in bulk for use in our service department, but it is also available in gallon containers from Mobil. The same product can be purchased from Detroit Diesel distributors under their own brand name.