2009 Prius getting 36-37 MPG

Prius has horsepower! If you stomp the gas, you can definitely get low mileage.

That being said, the Prius has a computer memory. The car analyzes your particular driving style, and optimizes it's performance to your driving style.

I drive mostly in the city. When I take a long distance highway trip, my mileage improves about 5-8mpg after I've been on the road for 200 miles. The car's computer adapts to the new conditions.

Learn to take it easy on the throttle, and let the car get used to you.

Also, if your fuel is highly oxygenated (for high pollution areas) that will eat into your mileage a little.

I have found that four things kill my mileage (I've had mine 2 months or so).
1. Rapid acceleration. You want moderate acceleration. Try to keep your mpg in the 20s duri g acceleration.
2. Speeding. I just gotback from a roadtrip to Yellowstone. Lots of open interstate with 75mph speed limits. I get horrible mileage over 65mph.
3. A/C. Turn it on and your mpg will go down.
4. Short trips. You get your worst mileage in the first 5 minutes of driving, until the engine warms up.
5. Don't use B-gear unless driving down steep grades (of which I imagine there are none in FL).

I upped my tire pressure to 3psi over the recommended. Go too high over the recommended psi and your have a rougher ride and shorten tire life.

Work on your gliding and warp-gliding when going over 45mpg. Gliding is no arrows. Warp-gliding is arrows from the ICU to the battery and the wheels, and having minimal pressure on the accelerator (great for freeway driving). Maximizing glide and warp-glide times will greatly I prove your mileage.

By working on the glide and warp-glide I can regularly get 55 - 59mpg for a tank.

People, "rottiepaws" lives in Florida! Running the AC during summer months is probably not optional.. :)
Just might have to live with lower mileage during the summer if the AC is what's killing it...

B-gear doesn't shut off regenerative breaking, but it can make it less efficient. I used it all over Yellowstone 1.5 weeks ago. I have discovered, though, that if the battery is less than half charged, it seems to recharge the battery with regen braking normally. But if more than half charged, it wastes a significant portion of the regen braking.

It was great, though. There is this stretch of road north of Dunraven Pass on the Grand Loop. I got 100mpg for 20 minutes.

But I digress.

The AC shouldn't take him all the way down to 36mpg. I drove 220 miles from Salt Lake to Wendover and back yesterday. My speed was roughly 78mph and I had the AC on (because I was driving through the desert). I still averaged 43mpg for the trip.

It seems to me that a number like 36-37mpg is probably more due to aggressive driving than anything else.

I have a 2009 prius and live in South Florida. I drive slow(under posted speed limits) and with the air conditioner on I only get 34.5 mpg. I have 3200 miles on my prius. I am extremely upset over my gas mileage. I had a 2007 prius that I always got over 50 mpg. Last week I went to the dealership and inquired on this. I was told that my car isnt even broken in yet.Also, with 10% ethanol in the gasoline that it is keeping my gas mileage low.They also filled my tires with nitrogen. Nothing helps!!!

I searched around some other forums. Supposedly in theory, E10 will drop mpgs by 3%. That calculates out to about 2 - 3mpg.

But in a lot of the forums, people complain about loosing 4 – 5mpg with E10, E15, or “winter blends” of gas.

I also read a post that said the older owner’s manuals recommend 87 Octane with E10 or E15.

Cross winds, reportedly, will reduce mpgs.

AC will definitely cost you 4 – 5mpg. AC costs you more mpg at lower speeds because you can’t glide as far. The higher the fan speed, the more mpg you will loose.

On the other hand, you do want to run some AC if it is hot because the EV fan uses cabin air to cool the battery. If the battery runs too hot or too cold, it will affect the mpg.

One other thing is I’ve seen some posts that say, give the hybrid system 6 months – 10,000 miles of break-in time. Some people have a 10% - 15% increase in mpgs once the hybrid system is broken in. Most of the impact seems to occur in the first 2,000 miles.

I started off with around 40mpg on my first drive home. I got up to 58mpg. Now that summer has finally hit here and I need my AC, I’m down to 52mpg.

I’m guessing my commute is a strange one to you all. In the summer, in the morning, its usually less than 70F, and I’m driving 90% downhill all the way to the office. (I live in a box canyon and my office is in one of the lowest parts of the valley.) In the summer, in the afternoon, it will be mid 90Fs – mid 100Fs and 90% uphill all the way back.

So on my way in, I’ll average 75mpg-ish and on the way home I average 30mpg-ish.

One change I made on my commute was to use an expressway instead of the foothill highway. Traffic is worst on the expressway and there’s a stoplight every half mile. But in rush hour, traffic speed is better for gliding. On the foothill highway, I lost a lot of mpgs on the uphills, too much for me to make up by coasting on the downhills. The expressway has flatter grades, so I don’t loose as much mpg on the uphills.

Traction vs Mileage is a compromise.

High traction tires (winter snow tires/off road tires) tend to have much higher rolling friction. And lower mileage.

the skinny high-pressure tires that get great mileage, tend to handle poorly in deep snow, ice, mud, ect.

Up here in Upstate, NY (yes, we do get snow in the winter) I use summer and winter tires. When I put the deep lug, lower pressure tires on for winter, I loose about 7 or 8 MPG on average. Just from the tires, not including road conditions.

Prior to the trip we're on we regularly got about 48mpg on our 2006 prius. We traveled about 3000 miles with 2 surfboards and a cargo carrier on the roof. We expected to get less mileage due to extra weight , freeway speeds and wind resistance. We averaged about 30 mpg. However, now that we have removed the surfboards and the rooftop cargo carrier, mileage is still hovering around 31 mpg (we're still on our first tank of gas without the load). The car seems to run fine. Is there something wrong with the car, or does the car's computer have to learn to drive efficiently again? Any insight would be appreciated.