I think recently(in the last few of years) Honda received new recommendations for oil application and they tend to put 0w20 everywhere now, because of fuel economy, environment etc. General consensus for fn2 is 5w30/5w40 grade.
Was going to post a thread about this but saw this one and thought I'd add to it.
Took my FN2 to local Honda main dealer today. Slightly alarmed that Castrol Professional 0w-20 had been used rather than the usual 5w-30 but tech confirmed correct. Upon review even Cox now have it listed on their site here:
The date June 20, 2013 just above, is the date this Blog was first started, NOT the date of the information included. It is regularly updated with the latest information, as indicated by the date s…
8. 0W40 vs 5W30 vs 0W30
As you can see from these actual Engineering test values, all the 5W30 oils provide better wear protection than any of the 0W oils. But even so, any of these oils would be acceptable for normal daily driver use. However, for highly loaded High Performance applications where the best possible wear protection is desired, the obvious choice would be 5W30 Pennzoil Ultra, API SM or 5W30 Mobil 1, API SN, which are the only oils in this test that provide INCREDIBLE wear protection.
From Total oil web page - In practice, this means that each oil is just as viscous at lower temperatures and will remain viscous at -30°C, however 5w40 oil outperforms 5w30 oils at higher temperatures, being effective up to temperatures of 50°C, as opposed to 30°C.
5w40 and 5w30 motor oils have winter viscosity grades of five, meaning they are effective down to temperatures of -30°C, and are more viscous at very low temperatures, compared to, say, 10w40 oils.
Resultantly, 5w40 oils are likely to be used in higher-performance engines that have higher operating temperatures and loads than the norm – those driven in urban environments, that commonly sit in traffic or driven at particularly high speeds, for example.
If your vehicle is not designed to be driven in a high-performance manner, or you drive at a more considered, environmentally friendly pace, 5w30 oils are a good choice. These are commonly better for certain engine components such as oil pumps, can clean the engine better, and have longer lifespans due to having a lower temperature range........ - So 30 weight is for Ambient temps up to 30 before it reaches its drop point. I'm not sure about this in the Honda manual it says 30 and 40 weight are ok about 40 c I suppose total doesn't account for engine cooling - hence ' if your sat in traffic or slow urban driving' - then 30 w 5w 30 or 5w 40 still unsure.
Yes I've settled on 5w 30 also. In the UK like you say the 30 weight will flow better at operating temps in UK. Up side also maybe cleaner, less pump strain ect. Better flow same film strength. Thanks for the post 👍