OAI VOA Mobil Delvac 1 ESP 5w40

Dec 15, 2010
San Antonio,TX & Leadville, CO
I've been running this in 2 unleaded vehicles. It's dual(spark & compression)rated. OAI flags oxidation when it rises 10%.
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The low Calcium means it would avoid LSPI in gasoline engines. In fact the VOA looks like a 2nd generation dexos1 oil additive package.
Extra ZDDP there compared to most SN oils. As long as the engine didn't burn much oil your catalysts would be fine though.
Should get excellent wear and longevity out of this, although its too thick for many gasoline engines.
An oxidation of 33 might mean some esters Group V oil is present, which is good. No problems here.
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The 2 vehicles don't burn any oil to speak of.

In 2018 Mobil had a mail-in rebate program going on for this oil. Between their discount and my NAPA discount, I stocked up on it for around $10/gal. Now, in 2019, Mobil is having another mail-in rebate deal. So, now I've stocked up on Mobil Delvac 1 ESP 5w30. Between an O'Reillys 25% discount and Mobils rebate this oil will cost me $13/gal. See their "terms and conditions" for "participating retailers"..

You can find a UOA thread here that I made a week or 2 ago about the 5w40 in our 07 Yukon Denali w/6.2. I'll start another thread here soon in the UOA area about the other vehicle, an 07 Toy FJ Cruiser w/4.0.

Currently I've switched the 2 vehicles to the Mobil Delvac 1 ESP 5w30.
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I'm guessing this is the new or current Grp III D1 ESP CK-4 formula as I've never seen it with Moly. Oxidation is almost 3x higher than the old CJ-4 formula.

D1 historically had a 60/40 blend of detergents, Calcium and Magnesium. Not much has changed except calcium has been reduced by 10% and magnesium is up by a similar amount.Nice shot of ZDDP too.
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