san2000

I shouldn't really should I??

After my 36k service a month ago, the garage filled up with Mobil 1 0w40.
Running low today (half way down markings on dipstick despite it being ok a week ago!), so filled up with my usual Shell Helix Ultra 5w40.

May just be in my mind, but I felt a huge difference with VTEC engagement and 'kick'. But, am I right in thinking that, if anything, 5w40 would provide less lubrication (as it would be that much thicker) for the change in cams, and so engage VTEC 'less smoothly'?

AquilaEagle

I doubt there would be any noticable difference between the 2. It's not about how much lubrication they offer, but the viscosity of the oil at temperatures.

Paper Lawyer

I think you simply remembered to release the handbrake this time San I very much doubt you (or I) would notice any difference at all between those two oils.

P 1

:edit: with AE (Craig snuk in there!)
The first of the two viscosity figures (i.e. 0 / 5) relates to viscosity when cold.
At normal operating temperatures I would have thought there should be no difference, especially as they are both 40 rated.

san2000

Hmmm....thought as much.

Didn't hear any friendly beeping, Craig!

Ian...presumably the viscosity affects the lubrication? No? I'm confused!

douglasr

Ehhh...no. Probably more to do with air density, humidity and temperature.
There is a lot of coool dense air over the UK at the mo - its from a high pressure system that passed over Greenland a few days ago - hence the low temperatures and the chance of frost overnight in some northern areas.

http://www.bbc.co.uk/weather/ukweath...perature.shtml

s2uk

when i changed from honda oil to redline i felt the car was smoother, engine runs better. if that makes any sense.

san2000

Aha.....Greenland! I knew it served a purpose!

AquilaEagle

douglasr - do you know S2000Mike in a professional capacity?

baptistsan

VTEC works off oil pressure no? So if you were low then it wouldn't feel so strong.