Would it be safe to run 0W30 in a Taco that specs 5W30? 15,000 miles on my 08 with the 6 cylinder engine. Conservative driving style and trying to obtain a 7500 mile drain interval with Mobil 1 product. Maybe even 10,000 miles. Anyone think that this engine can drop down to a 5W20? Looking for a slight gain in gas mileage and a larger OCI. Whadda you guys think? I currently have Mobil 1 5W30 in the block with 6,000 miles on the clock. Heh that rhymed. And the oil is still a slight amber color that has a twinge of graying.