Tires: new tires affecting MPG, weather differences, internal friction

Question
Hi Barry,
Is it possible for four new tires to have a negative effect on MPG? Tire pressure is checked with the same gauge as before, same tire size/rating as old tires, both all season tread (though design is slightly different), and I have taken into account colder weather differences. Vehicle is an F-150 and the difference is about 2 mpg since new tires were put on. Perhaps the fully treaded tires have an effect on the odometer/speedometer readings when compared to worn tires? Thanks.

Answer
Eric,

Original Equipment tires are frequently designed for good fuel economy and what usually gets sacrificed is tread wear, wet traction chip/chunk resistance, or a combintaion of those.

But replacement market tires - and since the design is different it will be a replacment market tire - do not give as good fuel economy, but the propeties I mentioned will be better.

But new tires will consume more fuel than worn out tires.  It has to do with the amount of internal friction (friction within the tire) and since there is less tread, there is less internal friction.  It has nothing to do with the odometer.