Community Forums:

At 75 MPH you can expect 23% lower mileage that at 55MPH, the speed often used for mileage figures.

Cars with smaller engines suffer more difference than cars with larger engines.

Often Consumer Reports tells you to order a larger engine than the smallest offered when buying a new car.

Hybrids are mostly designed for city driving, or driving in heavy traffic, some actually cite better city mileage than highway.

Perhaps your car is not broken in yet.

You should ask your dealer if higher pressure will disrupt your TPS - I think that they will adjust to the new pressure.

Be more careful with your tire pressure than in the past, low profile tires are more sensitive to changes, causing abnormal wear.

I recommend getting one of those battery boosters that are in a box about the size of a battery that has jumpers, a compressor, light, phone charger, a small inverter, etc. I find it quite handy to adjust air pressure - It runs a bit to bring a tire up 5 psi, but it does the job.