5w50 vs 10w40 oil - observations

[shlim8]

I just changed engine oil. Was previously using voltronic 10w40 oil, now on elf 5w50.

What a difference... previously upon startup, there was a clatter for a few seconds and after warm up, there is a louder "sporty" note to the engine. More free reving and with a slight flex of the accelerator, the tip downshifts immediately.

With the 5w50 oil, there is no clatter and the engine is totally civilized and quiet even. Sounds totally smooth and "sedan" like... The downside is that it's less free reving and needs a heavier foot to get downshifts....

While it's logical with the heavier weight oil for the engine to be quieter, I was rather surprised that the tip box is now slower to downshift.... is this normal ?

I wasn't expecting so much difference (prev oil was only 2 months and 5k km old).

[shlim8]

Oh, I used to get a smokey start every 5 or 6 starts, especially if the prev start was accompanied by just a short eninge run (ie shifting car out of driveway to wash).

So far, after 10+ over starts, still no smoke. Looks like prev oil may be too thin for the climate here.

Actually my current engine oil change was prompted by the smoke I was getting... thought it was slightly overfilled... mechanic suggested I change the oil instead.

[Steve Tinker]

My engine dislikes xxW50 grade oil - I tried Motul 15W50 oil earlier this summer thinking that is would handle the sub-tropical heat here better than my Shell Helix Ultra 5W40 grade oil. How wrong I was. Acceleration was noticibly more sluggish - so I dumped it after only 200km and filled up with the Shell again. The difference was immediate - engine back to its old self. And I've had the same experience with a couple of my motorcycles, both on the road and on the dyno. I should have learnt
No more high viscisity oils for me.