[watercutter]

after changing my oil, oilfilter, airfilter and tires to fusions my gas mileage dropped from an even 52city/52 hwy at 73mph it has now dropped to a 41 hwy/ 37street. im at a total loss please help

 

[hyperion]

Only thing that stands out are the different brand of tires. There are long threads on this subject and most go directly to the tires.
I guess the moral of the story from everything I have seen written here is "don't fool with a good thing."
Of course there will be admonisions that you have over filled your oil by a tenth of a quart and that kills milage and maybe your tire installer put in something like 26PSI of air instead of the 35/33 and that will do it. But it is usually the different brand of tires.

 

[David Beale]

New tires will give you a mileage hit. Wait for them to "break in" (perhaps a few thousand miles). Colder weather is also here, and that causes a mileage hit. I suspect your drop is caused by a combination of the two. Check the air pressure, as hyperion says, it may be low.

 

[DanMan32]

I'm suprised you got such good numbers doing 73 all the time. If lately you have done mostly highway, where before there was a great deal of moderate (30-50MPH) driving, that will make the difference too.

 

[jdenenberg]

The Bridgestone Fuzion Hri looks like a good all season performance tire, but it is not optimized for good MPG. It uses 'long link carbon' to maximize tread life. Low Rolling Resistance (LRR) tires usually replace much of the carbon in the rubber compound with OrganoSilicates. This sacrifices some tread life for lower rolling resistance.

Since your new tires have a Max PSI rating of 44 (cold), try running them at 42 PSI front and 40 PSI rear to see if you can regain some of the lost MPG. Good luck.

JeffD

 

[RichardF]

Is it at all possible that the new tires are a different diameter, i.e., a bit larger? That will make the new mileage appear worse even though it may not be as bad as indicated.

 

[efusco]

Yup, speed, new tires, probably wrong tire pressure, and now colder weather setting in are all likely factors causing you to see the lower mpg. If you've had a few shorter trips that could be it too.

Be sure to check the oil level, if it is significantly over-filled that can also impact FE.

Give those tires a few thousand miles to break in, pump them up to the 42f/40r as others recommended, do a little 45mph trip lasting around 30 min or so with as little traffic and as few stops as possible and see what your mileage is then.