First Oil Analysis

[JFP in PA]

Originally Posted by alm001

Would you care to expand on this? Are you implying my cat is likely to fail prematurely if I'm burning some oil?

Will the additional detergents give me issues?

From personal experience, I feel the impact of ZDDP on cats is way overblown. We have customers that have only run high ZDDP oils in engines that regularly consume some oil, after 165,000 miles their cats are fine. At the same time, newer cars running low SAPS oils (read little or no ZDDP) continue to suffer cat failures that are traced to the use of crap gas rather than oil additives.

Does ZDDP getting into cats have an impact on their life expectancy? The answer is yes, but those test were basically drowning them in ZDDP to see what happens. Hell, if you take enough aspirin it will kill you, but long before you reach fatal levels you would be so sick to your stomach, you would puke it all up. The test run by the car makers to get the EPA to start limiting ZDDP use in oils is based more on the fact that the car makers are on the hook to replace the cats for up to 8 years or 80K miles, then on real world oil consumption. To even approach the ZDDP exposure used to show the effect, you would have to have a car that burnt oil so bad it would look like a mosquito sprayer, and then drive it for half a million miles.

At the end of the day, your trade off is possibly having to replace cats, which can be changed in your driveway using simple hand tools, or a new engine. I know which I would choose.

The extra detergent will only clean out any build up in your engine, which might frighten you the first time you saw the blackened oil, but it would have no other detrimental effect.