Changing oil ratings ?

afer_daily, Mar 29, 10:42pm
got a car that was originaly specd 10w / 40 . done close to 400 ks . is it going to do it any harm to go to 20w ect ect oil

tweake, Mar 30, 12:07am
thats viscosity rather than rating.
whats the oil pressure like? no point going thicker oil unless oil pressure is getting marginal. the trouble is the thicker the oil the less flow you get and flow is what protects. as long as your above minimum oil pressure don;t worry about it.
also the higher the W viscosity (ie 20w) the thicker it is when cold which can mean more wear and more fuel usage if you do a lot of short trips (oil doesn't get up to temp). but also that a narrow range oil like 30w40 generally lasts longer than a 5w40, bu the 30w40 is more suited to an engine that is constantly at running temp. the 5w40 will handle cold running a lot better.
hope that helps :)

afer_daily, Mar 30, 7:45am
bump jeez come on 1 reply some one must know something ( good or bad ) ?

sterid01, Mar 30, 8:04am
If it's using oil put 20/50 in it .
if it still uses oil put in a bottle of morreys as well .

tweake, Mar 30, 9:10am
technically its bad. but if the engine is buggered whats there to loose ?

kazbanz, Mar 30, 9:45pm
There is no generic one size fits all reply. But if the vehicle is VVTI then yes going to 20 w 40 WILL cause issues. if its not VVTi then no worries

afer_daily, Mar 30, 10:35pm
its a 2002 with close to 400 ks on the clock / i was thinking that there would be enough wear to cope with it . ex corporate cab fairlane

kazbanz, Mar 30, 10:58pm
Talk to ford -but 400k in a fairlane--the engines ALMOST run in now.

tweake, Mar 31, 4:36am
proper way, fit an oil pressure gauge.

i ran thicker oil on mine for a bit, but even when hot, the oil pressure was to high and the bypass kept opening, that meant the engine got very little oil through it.

afer_daily, Mar 31, 4:43am
the oil pressure is still the same as before i did the oil change / mind you i have no idea what grade was in it before i changed it . 5 owners so who knows

kazbanz, Apr 4, 9:08am
My worry is the VVTi not working come winter time--and working badly even now