My mileage went south after I replace tires and did software upgrade a few week apart. From solid 40-42 to 35-37 (mileage driven/gallons).I did not go for LRR tires thought. But sometime I feel that something is causing drag,engine sounds like it stuck in lower gear. I used to see "optimistic" mileage after filling up, when I would get 60+ mpg driving in traffic/low speed limit street. Now it barely hits 40 and I'm not convinced this is caused by tires alone. I looked at 12V battery, etc. Perhaps I look into brake pads. Any advise would be appreciated. About 2 years ago I did Seattle -San Diego trip and mileage from Seattle and Reading was in 36 mpg range. But I spent a little over $200 woth of gas on round trip. Planning another trip to Yosemite national park this spring and will share observations.
You replaced the tires with an ill advised choice. There will be a slight improvement by the time they have 10,000 miles on them. And in 60,000 miles you can make a better choice. It is not helping that you seem to be using different units to measure your MPG. "About 2 years ago I did Seattle -San Diego trip and mileage from Seattle and Reading was in 36 mpg range. But I spent a little over $200 worth of gas on round trip." I suggest either MPG or just gallons, but comparing prices to MPG will confuse us and you.
What you are experiencing is absolutely normal. And in case you follow up with why you never experienced this in your previous cars. It's a 5.5% difference, meaning at 25 mpg, you'd drop to about 24 mpg. You wouldn't notice that. Add not being LRR and you arrive at the mpg drop you see. Fuel Efficient Low Rolling Resistant Tires
I leave you poorly tires and traction with high thickness. genuine because the 60000 km long road safety increased and avoid greater risks. not to mention the sharp turn at the board anymore corrosion tires
