Gotan oil change very recently,sprang a few extra bucks to getsemi-synthetic ... after using conventional exclusively to this point. Checked the oil level, it is exactly where it should be.

Theengine seems tobe performingdifferently. On the freeway,I've beengetting 38-40mpg (per the trip computer) - amazingly good, obviously. But the stop and go mileageseems to becouple MPG lower than what I usually experience.

I have read that sometimes synthetic oil needs to "break in" before it lubricates as well as it can - would the same apply to semi-synthetic oil? Any other comments?

 

Ford has been using Semi-Synthetic 5w20for years in there vehicles, from what I heard it helped get the MPG up a couple of miles.
As for a break in I don't believe it is like the Synthetic, but my 3 will be getting it also.

 

Hmmm, wish some others would chime in.

 

Ah, nothing to add?? (Can you believe that coming from me? )
I've used conventional oils and synthetic oils, both, but never have I tried the semi's.

 

I may have figured this out. I got the tires rotated at the same time the oil was changed. Checked the tire pressure very recently, all tires were in the mid 20s psi (in other words, low by quite a bit). My working theory is when they checked the tire pressure, they adjusted it down improperly. Can't they do anything right?

I have inflated them up to where they should be, I can feel a positive difference already.

 

The Dealership adjusted the pressure on mine when they did the before delivery inspection, the third day the TPS light came on, temperature was in the mid 20's, checked the tires and they were in the low 20's. I inflated to 35 PSI on all 4 corners and it was getting 2-3 MPG better all the way around.

 

Similar thing happened to me with my Mazda MPV. I service the car at dealership, until I found it out earlier this year, I never imagined that the dealer would mess it up. The proper pressure for my MPV is 35PSI, they always adjust it to 28, I caught it because they, for one time, wrote it down on the work sheet. Before that I always wondered that I seemed to lose air after oil change, never thought it was the dealer. Imagine if we inflate the aircraft tires like that. Those bozos.
________
Hyde Park Residence 2 Prathumnak