My previous daily driver was the 2002 S60 but in Sept 2017 my wife got another car and now I have her 2007 V50. Before the S60 I was driving a (very good condition) 1990 Jaguar XJ40 (also known as an XJ6).

The Volvo had a flat head 4.0 engine.

All the cars mentioned above are driven in my same daily routine which is mostly stop / go around town.

1990 Jaguar MPG was mid 15 (199,000 miles on odometer) non turbo
2002 S60 is sitting at 17.4 (223,000 miles on odometer) turbo
2007 V50 is sitting at 15.4 (103,740 on odometer) turbo

The V50 seems to be running well but last week it dawned on me that the MPG seems low. I use premium and full syn oil.

Last fall I had the PCV system replaced under extended warranty. When I retrieved the car from the dealer they had only replaced the box, nothing else. Volvo USA warranty said that that under the extended warranty the hose was to br replace and the intake O rings, etc.

I called and the dealer said bring the car in and they will take care of it. Retrieved the car and they gave me a $50 gift card to be used at the dealer. Checking the car they forget to tighten the one hose clamp on the big hose that goes over the top of the engine.

So here I am thinking about this mileage thing and I am wondering if they did the O rings correctly, did they pinch one, is there something else at hand, etc?

No CEL.

I can't believe that I am not getting better mileage than the big, 4,000 pound, 1990 Jaguar that was a 4 speed auto without OD.

Maybe this mileage is as good as it gets?