I buy Delo 15W-40 by the 6 gallon lot at Costco, and i'm on my last ARX cycle. Is it fine to run 15W-40 in this engine? I'm running Chevron 10W-30 in it now.
I recently put Delvac Super 1300 15W-40 in my LT4 Corvette with 45,000 miles on it. Engine runs great and doesn't burn oil between changes. The dipstick level didn't change noticably in 6,000 miles on M1 5W-30. It appeared to drop less than 1/10 of the way to the add mark.quote:
Originally posted by cheeks:
I currently run Delo 10w30 in my '99 Suburban 5.7L.
I am tempted to run 15W40 in it because it's relatively cheap and easy to buy a case at Sam's instead of ordering the 10w30 through the local Chevron jobber.
I've said before as far as MPG goes, I believe this sealing effect cancels out the added drag of the thicker oil. The trick is to find the balance that works best for you. Newer car means less need for the sealing, so lighter lube works well.quote:
I consistently get a little better mileage with 15w 40 Delo. I suspect because of better ring seal