Top 100: New Oil Preserves All Engines

Castrol reinvented its premium heavy-duty diesel oil with a high total base number to neutralize the acids created in EGR diesels, but low ash content to preserve all the engines out there that don't have the new emissions-reducing technology. Castrol replaced its tried and true Dieselall product with Tection Extra. The 15W 40 has a total base number of 12 and the ash content is 17 to 25 percent lower than the product's primary competition. Estimated price: $4.50 for a gallon of Tection Extra bought in bulk.