No Gain In MPG

The key to better fuel economy is your right foot and constant vigilance. Want proof? Read the economy threads and try it yourself.
Lowering the oil level works if it is too high and costs nothing but injector cleaner? I never saw anyone recommend that in a car with only 30 to 40,000 miles on it to improve economy. If your car had 100,000 miles on it and you used poor quality fuels I'd say injector cleaner MAY help.

 

Walker1,

A couple of things to keep in mind:
1. There is a break-in period for the tires themselves as has been mentioned in many threads. I've seen different explanations for it, and don't doubt that the observed effect is real. For me on other vehicles, new tires have always been stickier on various surfaces. Old tires that have been on the car for a few years just don't stick as well for me even though they are often the same exact model (not OEM though.) I don't doubt that they have lower rolling resistance as they age. The rubber compound tends to harden as tires age and that makes them less grippy in my experience. (Others' experiences may vary.)
2. Since manufacturers don't report rolling resistance and there isn't a specific test and rating to put on the sidewall, accurate information is difficult to find.
3. Injector cleaner would only make sense if you had seen a gradual decline absent anything else. I've never had injector cleaner do anything noticeable to any vehicle I've owned and I've tried it several times.

 

I recommend changing gas stations if you have a major brand on your route that offers a discount when using their credit card. Because there are too many variables I can't prove that changing to Shell helps the Prius FE as the Intrigue's hasn't moved at all. However, after the 5% rebate there isn't cheaper gas (for me) anywhere.

 

If it is 25 cents cheaper then it contains ethanol. You are fortunate to be getting the mileage you've been getting.

 

Your experience sounds like mine. Aging of the traction or 12V batteries can also reduce fuel economy. Everything gets old and wears out.

 

Wow, I can't put my AC above the level past LOW before I start chattering. And this is in 90 degree temperature, though I'm sure now as humid as what you have to deal with daily.