Originally Posted By: Indydriver
Originally Posted By: harrydog
I plan on keeping this car for a long time so I want to do what's best for the engine but I can't help thinking that better MPG is the main reason that Honda specifies 0w-20.
Granted, the four is a much different engine from my VCM V6 but I wonder why you think you know what's better for your engine than the Honda engineers who designed it?
The whole Honda break-in\OCI program was foreign to me as well. In addition, I was seeing too many reports of excessive oil consumption, fouling plugs and even complete failures in the VCM engine. So, I decided to follow the factory recommendations to a 'T' , use only Honda Genuine Full Synthetic and do used oil analysis at each change to learn as much as I could about what is happening in this engine. I learned a lot.
For starters, the myth of a super break-in oil from the Honda factory is just that, a myth. The fact is, the FF does not have as good an add pack as the aftermarket COP-made Honda brand oil I'm using now. The one difference is that Honda has a process whereby their piston skirts are impregnated with moly that slowing dissolves into the oil. So FF used oil analysis will show elevated moly and Honda wants it in there for a full cycle because their engineers have determined that it is beneficial for the long term performance of their engines.
Secondly, I have proven to myself by testing used oil that Honda's MM. Does a very good job of predicting oil deg. We hit 15% at 6300 on FF and 6400 on the first load of HG. Based on the used oil analysis which showed some oil life left (as well as improving metals and fuel dilution) I will be taking future OCIs to 0% or about 8000 miles.
The car now has about 15,000 miles on it, runs great and burns zero oil. Bottom line? This old 3000 mile OCI guy has proven to himself that Honda knows what they're doing (big surprise, right?).
I don't profess to know what's better for my engine than the Honda engineers, I'm just questioning the reason why they specify such a light weight oil. Do you really think that the engineers all allowed to design and specify everything without input from marketing and accounting? Everything is a compromise.
With gas prices being what they are these days, fuel efficiency is a major selling point.
I'm not even saying that using 0w-20 would be bad in any way other than possibly not providing as much wear protection in a hot, high revving engine. The HTHS ratings generally are a good indication of how well an oil will perform under those conditions and most 0w-20 oils do not have a particularly high HTHS number.
So, while I don't think I know more than the Honda engineers by any means, I do wonder if there is a better choice than 0w-20 if fuel efficiency is taken out of the equation. What better place to ask about that than here?