Sorry Brun, but you in effect disagreed with your own findings....
what you are saying is.. at normal temp they are similar viscocity .. that is exactly what I said, and the engine spends most of the time at that temp..
the cold rating as you call it is irrelevent if the oil is within manufacturers limits.
Eddd, yes, exactly.. thats why they have a multi rating...
, and a pour point, omitted from Bruns figures.
The oil is chosen for the conditions the vehicle will be used in - temp ranges mainly..
The out of normal temp figures are of no consequence provide the lubricating effect is maintained.. thats exactly what the ratings are >!
As Brun again points out... the viscocity at normal operating temps is roughly the same.. thats exactly what I have been saying all along....
and Nick.. sheeeeeesh
Im with you on this one Brun. These ACEA ratings or whatever they are mean nothing to me. Nor is that chart representative of a Clio 16v, because it is applied to Renaults current range. It says so at the top. A valver is a ten year old design. Maybe we should be looking at oils specced for Fords Zetec lumps and try them in an old Cortina just for fun?
Try reading it again - the renault chart.. note the reference to the f7 etc. ??.. this is for all the range .!
If you dont accept ACEA and The Manufacturers figures you are really off base on your mechanical knowledge... they know FAR more than your misguided beliefs m8... sorry to be so blunt, but sometimes your comments beggar belief...
15W50 is a tried and tested oil rating that works on all the valvers I know of. Not too thin at 15W (and yes, I do know thats not the correct terminology, but it is the easiest analogy) and will maintain its integrity at high temp with the 50 hot rating. Any 16v or Willy owner knows how hot they run, Ive never known a normally aspirated sub-2.0 lump (from any manufacturer) to run as hot as the F7P or F7R engines. The bonnet vent is there for a reason and thats why the lump benefits from a 50 rating.
And Again here..
15w50 is an old design of oil.. yes, they are designed.. its not the old engine that needs old oil only.. its the old engine probably benefitting from a better design of oil.... the bit about how hot they run ??? I am sure Renault know too unless you have some knowledge they havnt ??. The bonnet vent IS there for a reason.. but its got naff all to do with the engine benefiting from a 50 rating... its to keep temps down due to the design of the front end ducting.. it works.. thats it.. no mystery.
Seriously, sit back and think... you are talking in riddles m8...
Joe