Ummm....I am getting 26-27 MPG......

Hi Quelle...,

How you run the AC can make a big difference. In stop and go, there is just not any extra engine operation to charge the battery, so the overhead of starting and running the engine is used only for climate control. That said, if you run Max Cool the engine will run allot. The beuty of the Prius climate control is the variable output capability. Read up on the controls in the manual. The Prius has a "desired" temperature control. So, you can set the temperature up to say 80 F. Which will run the compressor and ventilation fans at a much lower speed/power level, but keep things comfortable in the car. When you first start up the car, the AC and fans will run fast, but as the car cools down, the AC and fans will slow up automatically.

If you run the car a bit (take another route) before you come into a stop/go situation that will be helpful. Because the car will get a chance to put energy in the battery with the engine running at a more efficient power level. Low power levels are inefficient for gasoline engines. The Prius has a better engine in this regard, but running down the road, running the AC, and charging the battery is going to be way more efficient than stopped in traffic with a low battery, and running the AC. Stopped in traffic the AC condensor fan may need to run. Moving down the road, the windflow into the front of the car will do this for free, too.

Another thing to do is get a sun shade. Any extra cooling that the car needs to do when you turn it on uses battery, which uses gas. Even here in Illinois, I use one of those custom CA made sun shades to cover the entire front window. They sell them in the store here. And though $30 sounds like allot, it will make a big difference in the startup temps inside the car. And this will pay for itself, besides protecting the expensive electronics in the car. If you can park in the shade, that is even better.

Finally, I believe the car does some new-battery conditioning at first. Which is going to baby the battery, and you wont get the full performance yet.

 

wait until you've run 4,5 tanks through.
if you've only put on 50 miles , you don't know what mileage you're getting - maybe the tank was full when you bought it, maybe not. the fuel guage isn't that accurate.
after a few thousand miles, divide your miles driven by total fuel pumped in and see what you get.

50 miles in several weeks? did i read that right? your average trip must be real short - not giving the engine time to warm up? try resetting the mileage on the mfd and go for a 50 mile highway trip and see what happens.

 

Let's go over a few basics:

• What is your oil level relative to the "F" mark?
• What are your tire pressures?
• Does your gear selector show "D" or "B"? (A family member problem.)
• Can you get a wheel alignment check and bring results here?

I don't like to address driving style until after making sure the vehicle is truly healthy. You may find this hard to believe by my Prius was handed over by a Toyota dealer with the oil above the "F" mark; tire pressures of 32 psi; one family member who moves the selector all the way into "B" and skips "D"; and poor wheel alignment.

After making sure the car is in a good state of repair, we can address modest driving practices:

• Drive 25 mph for first mile or so to keep fuel consumption down and warm up the engine, oils and tires.
• Normal driving in the speed ranges of 0-38, 45-65 mph and avoid going through 39-44, a place where it can trigger unnecessary engine operation. I use cruise control to handle the speed so I can concentrate on traffic.
• Drive last two miles at speed under 38 mph and closer to 30 mph is best to use the stored battery energy that otherwise would be lost after being parked for more than 8-12 hours.

But don't adopt these practices without having the mechanical parts of the car throughly checked, especially since it is under warranty. You already know a rented Prius can deliver great mileage. You are now the 'maintenance supervisor' and can make sure your car does what it should.

BTW, what part of California? There are Prius experts across the country and the ones that post here are especially helpful. Perhaps not right away, let the dealer do the right thing, but when your happy with getting a little extra help.

Bob Wilson

 

Definitely go check the tire pressure and oil level ASAP. Tire pressures should be measured cold, so either buy a $10 gauge or go to a service station less than a mile away.

When you rented the Prius did you use it on the same route you're using yours on now?

Short trips of less than a few miles are death for MPGs in any car. Running the air conditioner in a Prius is insignificant in comparison.

 

I live in Florida and run the AC at 69 non stop and my mileage is always at 47 mpg's. AC does not affect this car that much.

Fill tires to 44/40.

Your running E10 gas which will hose you for 3-5 mpg's anyway.

Run only 87 octane. Cheap stuff. Anything better will give you worse mileage.

As Ed said: Sometimes a bad daily route stays in the cars memory for quite a while. If I pick around town all day stop & go it will take 2 days of good hypermilling on a highway to change the mpg ratio. Strange little car. Go on a nice long highway drive.

 

What cheese - in addition to the above ideas, since the car is on it's first fuel load, we can not rule out the possibility that the fuel was of low quality.

No proof of it, and no need to panic, but I would top the tank off. Easy to do and harmless, while awaiting more info on vehicle alignment, possible dragging rear brakes, etc.

 

Stop & go driving in hot weather with the A/C running (with the A/C in auto, how fast is the fan going?), you'll get poor fuel economy. Don't worry, that's still probably at least double the fuel economy of your last car. So I'm not too surprised to see about 35 mpg. Leave the A/C in auto and set to the highest temperature you feel comfortable at in hot weather.

44psi front and 42psi rear will help a little bit. From the dealer they're probably inflated around 32psi or so.

 

My lips are sealed.
those who know me know what I'm thinking.

 

Did you reset the mileage indicator after adding the air and before driving? The reason I ask is if your mileage indicator was at 26-27 MPG, and you now show 30.8 MPG on top of what you had, you'd have been running closer to 33-35 MPG over the 110 miles. This is less bad but still a problem.

GOOD LUCK!
Bob Wilson

ps. For our math buffs:

x miles @ Y_1 MPG -> (x/Y_1) gallons for x miles
z miles @ Y_2 MPG -> (z/Y_2) gallons for y miles

If z = x + 110 miles (the display was not reset,) then we take:

(z/Y_2) - (x/Y_1) = Z gallons for 110 miles
110 miles / Z gallons -> MPG for the 110 miles

 

Make sure the engine brake isn't on. See PRNDB display on instrument panel.. There shouldn't be a box displayed around the "B". It will really pull mpg down.

If after 500 miles your average isn't near 40 mpg I'd take into dealer.

 

Well, I would take it back to the dealer because there may be a fuel leak somewhere. I just picked up our new 2008 Prius last Friday and have just today passed the 100 mile mark and we are showing 42.9 mpg. The 100 miles is all just running around town, probably less than 10 miles of freeway driving and I have beaten a few other cars away from the green light so I'm not trying to baby it.

 

Hmm, I bet you have checked everything. If it is new, take it to the dealer and tell them something is way off. Ask them if they could take a look at it, check the computers and what not. However I think it would have lit something up if there were a code going off. It beats me, but I have heard other posts like this before. Sometimes there is what I like to call "a fart in the system." HAHA Well, good luck and don't be discouraged. Whatever the problem is, it should be fixable and you will be so happy afterwards.

 

Sure, a long steep hill could easily make that difference if you have driven it many times in the short time you've had the car. I would take it out on the highway at 55 and see what you get then. I think it should show over 50 mpg in that driving mode. I'll do that tomorrow and post my result.

 

And their pressure now is...?

 

Last week I had an interesting experience in my Prius. It was 100 degrees here in Boston and I had to drive to the train station to pick up someone coming to visit. For those who don't know, driving to South Station requires going right through the heart of the downtown area.

My lifetime average so far (after 2,300 miles) is about 55 mpg. On the highways I get ~60 mpg and on short trips through the city I get ~50 mpg (25 mpg for the first 5 minutes, and then 50-100 mpg for every subsequent 5 minute block).

On this particular trip I ran the A/C for the first time, set to 83 degrees, and it was some of the worst stop and go traffic I've ever experienced. It took me 40 minutes to drive 3 miles and I never drove continuously for more than 30 seconds. As a result I averaged 25-30 mpg for the whole 40 minutes.

From what you describe, going 9 miles, uphill, through very bad traffic, with the A/C running, my guess is that there is nothing wrong with you or the car. It's just the environment. If I had to make that trip everyday I would absolutely not be doing it in a car. Find another route. Or take a bicycle.

I simply do not believe that your old car got its exact EPA mileage when the Prius is performing this badly. Think about all the time when other cars are just idling and you are not.

Tim