[SentraSE-R]

Originally Posted by Old Mechanic

3. EOC will cause increased stress on some components. Catalytic converters suffer from increased heat cooling cycles. Sentra stopped using EOC when he found it was causing his emissions to increase dramatcially, to the point where testing showed long term effects (he is certainly free to add info, this is what I read from his posts). I don't believe EOC overstresses cooling systems. Obviously if you EOC enough to drain your battery if will shorten battery life, and if you use the starter more frequently, then, in my opinion you will reduce it's life expectancy. Repeated heat-cool events, beyond what is considered normal could also increase the accumulation of EGR-PCV deposits.

I did find my emissions went through the roof with long-term EOC. As a result, I stopped EOC for 6622 miles last Winter/Spring. I took a 6 mpg hit, but ran clean emissions.

I eventually rationalized I emit less pollutants in a year than an oil supertanker emits in .63 seconds, and we employ the equivalent of ~11 supertankers spewing pollutants 24/7 just to supply middle east oil to our refineries to supply the USA's thirst for oil. Ergo, I went back to EOC P&G.

One caveat about running thinner oils in older engines. Toyota TSB EG018-06 recommends 5W-20W oil in my '06 Scion xB's 1NZ-FE engine, but not in the '04 and '05 Scion xBs, which are equipped with the same 1NZ-FE engine. I'm guessing the newer engines have tighter and/or smoother bearing surfaces to run the thinner oil without damage.