40C is where the coolant temp begins registering in the car and the oil is warm-ish (not hot, but warm) so I'm wondering if that thickness in EFE really is a negative, so to speak. This is why oils like 0w20/30/40 both have good VI and are composed of real synthetic base stocks (because they have to be to meet the 0w20/30/40 numbers).Ĭrap I thought more reading would clear this up and I would just move to X-clean EFE.now I am more conflicted than ever.Ĭlick to expand.Those are interesting points, but as was said by bluesubie2, 40C isn't cold like startup temps. I definitely do much less spirited driving and less longer drives in the winter.well with the exception of the occasional hoon in fresh snow (ice covered by 6 inches of snow last weekend baby)Īccording to my recent reading, the better low temp viscosity and higher VI usually indicate real synthetic (maybe better) base stocks in comparison to some (most) 5w30 "Synthetics" that are ultra refined dino-oil-stocks. I wonder if my car ever really reaches normal operating temps for the oil (I don't have an oil temp guage) during these drives.īut I am sacrificing normal op temp viscosity to stay with the Sustina.and I think (THINK-who really knows) we can all agree that the EJ257 could use a thicker oil at operating temp. In the winter most of my driving is cold start (in garage) - 5.5 miles - cold start (in parking lot at work) - 5.5 miles home. So now I wonder if by going to EFE I am sacrificing startup/cold operating protection. one that is closer to the desired operating temp value) will protect better at cold temps than the lower VI oil because it flows better (more like normal) through the passages. It means that an oil with a better/lower 40C viscosity (i.e. The desired 30 wt (the 30 in 5w30) viscosity at operating temp is between 9.3 and 12.5.Ī higher viscosity index (VI) is better because it means that at low temps the oil is closer to the desired running viscosity.
![motul xclean fe motul xclean fe](https://cdn.otopark.com/2019/04/34458_4f30b049572e14fa9042b03549417709.jpeg)
![motul xclean fe motul xclean fe](https://http2.mlstatic.com/D_NQ_NP_672360-MLM31488591749_072019-W.jpg)
X-clean EFE 5w30 40C viscosity = 70.1 100C viscosity = 12.1 viscosity index = 169 HTHS = 3.5 I am currently using (but considering going away from to X-clean EFE)Įneos Sustina 5w30 40C viscosity = 51.5 100C viscosity = 10.3 viscosity index = 194 HTHS = 3.1 Viscosity that is ~25% higher than other oils with an HTHS ~3.0-3.1.
![motul xclean fe motul xclean fe](https://i.ebayimg.com/images/i/182867560507-0-1/s-l1000.jpg)
One thing that I have noticed is that while the X-clean EFE is a HTHS 3.5 oil it also has a cold