Anyone who deliberately deviates from the spec is just plain nuts. Whatever might be going on outside the scope ( place and / or time etc. ) simply doesn't apply. Does anyone really think they know better than Honda engineers who designed and build these engines ?! 0W-30 is simply wrong and certainly NOT changing up.
If someone can step forward with UOA's showing superior wear protection with 0w-20s, I'll buy it. These thin oils will certainly provide adequate protection for the average end user, but may not be ideal for every situation. 0w-30 is a decent alternative, providing similar cold start pumpability, but a bit more operating temp viscosity; this would be beneficial with aggressive driving, fuel dilution etc.
I think fleet averages for mpgs of vehicles sold in the US are the reason for these thinner oils.
, but it's a stressed engine compared to our cars.
I agree, I believe the tolerances are more consistent . . . and with improved metallurgy/surface finishing to reduce wear and friction aids oils in lubricating. Quick build-up in oil pressure is key to cold starts and seems that the thinner oils don't produce higher pressures, only in very cold situations. It appears that the MPG is the guiding force to recommending "thin" oils, excerpt from an article published in the "Wirecutter";I think fleet averages for mpgs of vehicles sold in the US are the reason for these thinner oils.
https://en.wikipedia.org/wiki/Corporate_Average_Fuel_Economy
I think tight tolerances as the reason for xw-20 oils is a bunch of BS. Yes, engines today have tighter, more consistent tolerances than 40-50 years ago, but piston ring, skirt and bearing clearances still have to allow for thermal expansion, oil flow etc. My 2016 KTM 690 has a "tight" engine, but the manufacturer specs 10w-60. Sub-freezing starts are a non-issue, because it's in storage
As I said : "Whatever might be going on outside the scope ( place and / or time etc. ) simply doesn't apply ..." If 0W-30 was OK or preferred, then Honda would certainly have included it. Out of spec heavier oils aren't going to get to bearings as well as the proper spec oils. Clearances are probably very tight requiring thinner 0W-20 oil.
Wrong. "tolerance" does not mean the size of clearances. It means the amount of variation.Clearances in the new honda engines are no tighter than clearances in any of the japanese automakers engines have been for the last ten years. The reason 0w20 is specified is in order to conform to the CAFE standards regulations regarding fuel efficiency claims by the automakers. In extremely cold starting conditions honda can legally claim an additional one mile per gallon if 0w20 is in the specification. Nothing to do with engine protection. In warm weather ambient conditions there's no reason not to use 0w30. And it's probably better.
I don't know much about oil but I do know that 0w-30 oil would be a little thicker which would make in useful for hot ambient conditions since less chance of degredation correct? If so, then what kind of oil would you recommend for South Florida where the weather is usually always 80+ F. Especially now we're getting 90+ F. In the harshest winter it goes down to about 50 F. I was going to use Mobile 1's Extended Performance OW-20 and I doubt they have that in OW-30 easily available.
In your case, and I am not an oil engineer, don't worry about the first winter weight rating "W" , 5W-30 or 10W-30 synthetic would be OK. I recently viewed my Honda Civic Owner's Manual regarding Maintenance Under the Hood section and checked the oil specification. Honda "recommends" 0W-20 for all ambient temperature ranges. Safe bet for the cold climates and raises fuel economy.
Just exactly where did I use the term "tolerance"? Could be I've forgotten, but I don't think so. My last statement is only speculation as clearly evidenced by the term "probably" .
You think engineers write the manual? HA!
