When was this engine first put into production? What wt. oil was spec'd for it at that time? Have the tolerances and clearances changed in this current engine since being produced originally? That's how you can answer your Q?, 5W20 or 5W30.
5w30 or 5w20 ?
- Thread starter actionstan
- Start date
- Status
Unless its a racing engine I think most modern engine run a bearing diametrical clearance of 0.0005 - 0.0020 - so that should not dictate grade. More toward piston controlring/skirt oil management, rod/main bearing area, reciprocating mas at max rpm, oil pump volume, tappet blead-down rate, vvti oil porting/ assy return spring etc.
4 cyl length inline block/crank have a inherent runout and tol stack limits (static and DYNAMIC) where you really cant go tighter than .0005 on the mains.
4 cyl length inline block/crank have a inherent runout and tol stack limits (static and DYNAMIC) where you really cant go tighter than .0005 on the mains.
Originally Posted By: ARCOgraphite
Unless its a racing engine I think most modern engine run a bearing diametrical clearance of 0.0005 - 0.0020 - so that should not dictate grade. More toward piston controlring/skirt oil management, rod/main bearing area, reciprocating mas at max rpm, oil pump volume, tappet blead-down rate, vvti oil porting/ assy return spring etc.
4 cyl length inline block/crank have a inherent runout and tol stack limits (static and DYNAMIC) where you really cant go tighter than .0005 on the mains.
Makes sense. But, you always here the 5W20 Gods say to use 5W20 because of "tighter clearances and tolerances." If those tolerances and clearances have not changed in an engine when it was spec'd 5W30 why use 5W20, other than a glimmer of better gas mileage? I like the fact that I have an option to use either one.
Unless its a racing engine I think most modern engine run a bearing diametrical clearance of 0.0005 - 0.0020 - so that should not dictate grade. More toward piston controlring/skirt oil management, rod/main bearing area, reciprocating mas at max rpm, oil pump volume, tappet blead-down rate, vvti oil porting/ assy return spring etc.
4 cyl length inline block/crank have a inherent runout and tol stack limits (static and DYNAMIC) where you really cant go tighter than .0005 on the mains.
Makes sense. But, you always here the 5W20 Gods say to use 5W20 because of "tighter clearances and tolerances." If those tolerances and clearances have not changed in an engine when it was spec'd 5W30 why use 5W20, other than a glimmer of better gas mileage? I like the fact that I have an option to use either one.
Originally Posted By: BlueOvalFitter
Originally Posted By: ARCOgraphite
Unless its a racing engine I think most modern engine run a bearing diametrical clearance of 0.0005 - 0.0020 - so that should not dictate grade. More toward piston controlring/skirt oil management, rod/main bearing area, reciprocating mas at max rpm, oil pump volume, tappet blead-down rate, vvti oil porting/ assy return spring etc.
4 cyl length inline block/crank have a inherent runout and tol stack limits (static and DYNAMIC) where you really cant go tighter than .0005 on the mains.
Makes sense. But, you always here the 5W20 Gods say to use 5W20 because of "tighter clearances and tolerances." If those tolerances and clearances have not changed in an engine when it was spec'd 5W30 why use 5W20, other than a glimmer of better gas mileage?
Because motor oil has continued to improve as well over time.
Typically a companies 5W-20 is the same oil as their 5W-30 but with less shear prone VIIs. Plus the fact that viscosity of a 5W-20 at the end of the recommended OCI is likely higher than a 5W-30 of years ago.
Finally from a pure lubrication perspective it is usually best to use the lightest oil recommended by the manufacture. Even with the lightest recommended oil, the viscosity safety margin is huge.
Optional heavier oil grades has more to do with grade availability in hot climates. The heavier grades won't provide any better lubrication but the main advantages of a 20wt oil have been largely mitigated as have the disadvantages of the next heavier grade.
Here in NA the availability of 5W-20 and now even 0W-20 grades is universal there is no reason to use anything heavier.
Originally Posted By: ARCOgraphite
Unless its a racing engine I think most modern engine run a bearing diametrical clearance of 0.0005 - 0.0020 - so that should not dictate grade. More toward piston controlring/skirt oil management, rod/main bearing area, reciprocating mas at max rpm, oil pump volume, tappet blead-down rate, vvti oil porting/ assy return spring etc.
4 cyl length inline block/crank have a inherent runout and tol stack limits (static and DYNAMIC) where you really cant go tighter than .0005 on the mains.
Makes sense. But, you always here the 5W20 Gods say to use 5W20 because of "tighter clearances and tolerances." If those tolerances and clearances have not changed in an engine when it was spec'd 5W30 why use 5W20, other than a glimmer of better gas mileage?
Because motor oil has continued to improve as well over time.
Typically a companies 5W-20 is the same oil as their 5W-30 but with less shear prone VIIs. Plus the fact that viscosity of a 5W-20 at the end of the recommended OCI is likely higher than a 5W-30 of years ago.
Finally from a pure lubrication perspective it is usually best to use the lightest oil recommended by the manufacture. Even with the lightest recommended oil, the viscosity safety margin is huge.
Optional heavier oil grades has more to do with grade availability in hot climates. The heavier grades won't provide any better lubrication but the main advantages of a 20wt oil have been largely mitigated as have the disadvantages of the next heavier grade.
Here in NA the availability of 5W-20 and now even 0W-20 grades is universal there is no reason to use anything heavier.
You're right the manual lists 5w20 up to 10w30 as acceptable but it also clearly pushes the 5w20 as the preferred choice. We have a KIA under warranty and I'm running 5w20 in it for that reason alone.
Their OCI schedule is ridiculous, I am running full syn at near the max they allow at 7k, but I did a UOA to prove the oil was fine at 7k's worth of use.
I wouldn't mind short OCI's with conventional at all but the filters are expensive enough it is considerably cheaper to run full syn for 7k than conventional for 4k.
I will probably switch ours to a 30 grade when warranty is up and do a UOA to see if there is any difference in "wear" numbers.
Their OCI schedule is ridiculous, I am running full syn at near the max they allow at 7k, but I did a UOA to prove the oil was fine at 7k's worth of use.
I wouldn't mind short OCI's with conventional at all but the filters are expensive enough it is considerably cheaper to run full syn for 7k than conventional for 4k.
I will probably switch ours to a 30 grade when warranty is up and do a UOA to see if there is any difference in "wear" numbers.
Originally Posted By: BlueOvalFitter
I like the fact that I have an option to use either one.
^^^^^^^^^^This.^^^^^^^^^^
I like the fact that I have an option to use either one.
^^^^^^^^^^This.^^^^^^^^^^
Originally Posted By: 02s4audi
Now another big question, what brand would be best for this car?
The one that meets that cars specs. Haven't we been here before. Come on, this is silly.
Now another big question, what brand would be best for this car?
The one that meets that cars specs. Haven't we been here before. Come on, this is silly.
Originally Posted By: actionstan
In my manual it states i can use anything from 5w20-10w30.
For superior lubrication, run the 10W-30.
In my manual it states i can use anything from 5w20-10w30.
For superior lubrication, run the 10W-30.
- Status
Similar threads
