06 Prius, cant get over 41mph average.

May as well answer the questions from
http://priuschat.com/forums/gen-ii-...-answer-these-questions-esp-if-youre-new.html in this thread.

We also know nothing about your friend's cars (year, engine, transmission, fuel type), their driving habits including length of commutes.

Hopefully the mods can move this to the Gen II area as you do not have a Gen III.

 

That's the problem right there. Change it with synthetic and make sure it is filled up to the correct level.

Can you describe your typical trip? Distance, highway, city, etc...

 

Strange, I was getting 52mpg average on my '07, then went down to 46mpg after I upgraded to 17" wheels.

posted from my HTC Evo

 

Don't crawl away from stoplights and stop signs. Accelerate smartly, quickly up to speed, then ease off a little bit.

 

The easiest way to attract their attention is to hit the little "flag" icon to the lower left. Just describe the problem and soon enough, the magic will happen.

GOOD LUCK!
Bob Wilson

 

And he's not kidding. The oil could easily be grossly overfilled, or they may have used the wrong weight. Go check the level now. (Always check it yourself before driving away from every oil change. This will catch common stupid mistakes before they become expensive.)

Short trips and very hot weather will reduce MPGs, but *do* use the A/C. (The battery system draws its cooling air from the cabin; if you're not comfortable then neither is the battery.)

Was the car a Toyota certified used, or was it inspected by a Toyota dealer before you bought it? If not almost anything could be wrong.

Do you ever shift into "B"? If so, don't. You're about 500 miles from the nearest terrain where "B" might ever be needed.

 

Not strange. Larger wheels are heavier & tend to reduce FE. The replacement tires may not be LRR which will be another hit. Your new tires may also be underinflated. Fill to max sidewall pressure to get some of the lost FE back.

 

That's what we need to know.

My commute went from 40 minutes of 2-lane roads to less than 15 minutes of nearly all interstate @ 75-80mph.

I was averaging 54mpg. I now average around 45mpg.

The primary factor is HOW LONG of a trip do you normally take. Sans a block heater, all autos have to warm up. As they do, fuel economy is not on par with that of a warm engine. My Prius seems to generally get around 25mpg in this 5-minute warm-up stage.

With less than a 15 minute drive, over 1/3 of my commute is sans a warm engine. That is the primary reason why my mileage went down so much. If you have a similar commute, I'd expect similar numbers.

By the way, this has nothing to do with the Prius. All autos suffer from poor mileage during this initial warm-up stage.

-Brad

 

I had a Gen I that when traded in could only manage 25-30 mpg. Dealer conclusion: battery growing weaker requiring the ICE to "pick up the slack". Surely not in your case I hope.