can directional tires decrease mileage?

I was putting my winter wheels on today, and noticed that my front tires were on the wrong sides. I have directional tires, they have a little arrow pointing to the front of the car if they are on correctly.

Ever since I got my car back from having the clutch changed my mileage has been lower, so I thinking that maybe the mechanic putting my tires on the wrong sides of the car has somthing to do with it.

I guess I’ll be able to tell now that I have different wheels and tires on my car.

Yes, it’s entirely possible that they could. A unidirectional tire is made that way to decrease resistance in straight line acceleration. So putting it on backwards = most resistance=lower mpg.

After driving around today it seems like there might be a little less resistance. I haven’t gotten gas yet, so I’m not sure about the mileage.

It’s weird before I had the clutch changed if I was in 5th gear, going 60mph my rpms would be slightly below 3k, now they will be slightly above 3k. It might just be a coincidence that I noticed it after the clutch. The only way I think it could be related to the clutch, is that possibly the spedometer cable isn’t as tight as it should be. I’ve checked my tire pressure plenty of times and it’s always right at 32 psi. It’s not a huge drop in mileage I’ve gone from about 31 mpg to about 28mpg. My driving style didn’t change. If anything I was going easier on the car, to break in the clutch.