I think the jury is still out and exactly what will and won’t foul an O2 sensor. Earlier this year, my Civic Coupe developed some knocking and pinging. It was light but annoying nonetheless. Seeing as how the car had 115,000 miles on it, I figured the O2 sensor might be giving up the ghost. I ordered a replacement (not OEM but NGK/NTK … i.e., a good one) and installed it. So far, I notice no change.
During most of the car’s life (starting in ’95) it had Mobil 1 in the crankcase, mostly their pre-Tri-Synthetic formula. Towards the 100,000 mile mark, I tried Valvoline Synpower which was supposedly 100% PAO (but it’s not) with more zinc (1.5% - 1500ppm?).
Amsoil claims that oils high in zinc dialkyl dithiophosphate (ZDDP) will not harm catalytic converters if their volatility is very low (I forget the percentage they cite – 5%?). I guess low-volatility oils tend to stay in the crankcase and less of them make their way pass the rings and into the exhaust. Sounds reasonable to me.
Of course, they claim their oils fall into this category.
If they are a PAO-based formula, I suppose that is also reasonable.
I know the engine in my Honda Civic Coupe is amazingly tight. The car used no noticeable oil (almost exclusively 5W30) for the first 100,000 miles. At around that time I switched to Valvoline Synpower and began to notice a small amount of consumption – ½ quart in 5,000 miles.
Switching to Red Line not quite a year ago, the consumption disappeared after 10,000 miles. I suspect the seal swelling action of the ester base oil reversed the trend started by the Valvoline but I really don’t know for sure.
So, Red Line has a fair amount of zinc and a LOT of soluble moly (they won’t specify disulfide or disulphate but no visible trace remains at the bottom of the new containers when it is poured out). I will be monitoring my mileage and for other signs that my new O2 sensor is getting fouled but I don’t anticipate it happening anytime soon.
Back to the topic of the new SuperSyn and its patented anti-wear technology, I’m highly skeptical. Using older formulations of Mobil 1, my Civic developed an annoying “piston slap” sound at around 70-80,000 miles. This is wear of the piston skirts and is considered normal wear for this engine.
However I didn’t use a
normal oil, I used the much-hyped Mobil 1 which supposedly ran in a car for a million miles with virtually no wear to parts of its engine. As a result, I was not impressed with M1 Tri-Syn (and its ultra-low 0.075% ZDDP level) after that and I am reluctant to try another one of their mega-hyped synthetic oils.
Let someone else be their real-world guinea pigs.
SteveinSeattle, where did you find Red Line for $5.50 per quart?