Very Low Gas Mileage .... Why?

Please answer the questions at http://priuschat.com/forums/gen-ii-...-answer-these-questions-esp-if-youre-new.html.

Please definitely elaborate on the trip length in terms of time, distance speed, and terrain. I recall some areas around Folsom are quite hilly. Short trips will kill your mileage, esp. in the city.

Please definitely indicate what tires you changed to (make, model, size). It's very possible you've also changed to higher rolling resistance that will hurt your economy. Even if you switched to the same make and model, there will be some initial drop due to Tire Tech Information - Tire Rolling Resistance Part 3: Changes to Expect When Switching from Worn-Out to New Tires. Also define "properly inflated".

ConsumerReports.org - Most fuel-efficient cars is what Consumer Reports got in their testing for your generation of Prius.

 

I'd be curious to know what your daily commute consists of. You should be able to maintain a 45-50mpg average without much effort in the Folsom area unless you are making very short trips and using the HV battery too much.

I'd be happy to take a test drive with you and observe your driving habit as well as see if I can increase your MPG vs. the way you currently drive the car. Ultimately, you shouldn't be experiencing such low MPG numbers no mater how aggressively you drive unless you are not driving enough miles to complete the warm-up cycle.

 

The hills in Folsom should be no big deal. My commute from Rocklin to Auburn is nearly a 1,000 elevation gain and I can still manage 46mpg without trying and 48mpg if I try. Flatland trips produce numbers over 50mpg.

See the pic for my one-way uphill commute.

 

My 2005 Prius is also getting very low mileage, 35-40 mpg. When I bought it, and for about 3 years or so, it got 55-60 mpg consistently. Then I moved to western Oregon (wet) where they told me there are special gas additives because of the moisture in the air (?), and the mileage dropped to 45, which I think most people get here. Now it's 35 which I think is unacceptable.

 

As I answered before, please answer the questions at Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new.

Since you've moved, it's no doubt that you're commute has changed and possibly so have the weather conditions. Cold weather and short trips (along w/many other factors) hurt mileage.

 

Wouldn't the 12V battery going bad have a significant contribution to low MPG's? If the 12V batt isn't able to hold a good charge, doesn't that cause the HV pack to constantly support the 12V requirements by the car,...and if it's constantly having to use the stored HV battery power to power the electronics in the car, wouldn't the ICE need to be running to charge the HV pack more frequently, which would result in lower MPG's?

 

i believe so. ^

 

Yes, but this is just one of many possible reasons why a person might get lower than expected MPG's. That's why it's better that people answer the questions asked above by "cwerdna" instead of speculating about the very many different possibilities.

 

Oregon has made the mistake of increasing the ethanol content of its gas and according to my Toyota Service Manager that is the cause of my drop in mileage and possible the other Oregon Prius driver's low mileage. I struggled with the decision to add ethanol and campaigned against it but our Gov was sold a pile of *&&%% and led us down this path. Many studies confirm the drop of 10-15% in efficiency for most vehicles when using ethanol.

 

Yep. And all too often, people complaining about their mileage either never return and/or don't answer any of our questions. Result? A lot of wasted effort on our part.

 

Well just think of the upside. People are complaining about 35mpg being bad! When expectations are raised, it is good for everyone. If you are angry about not getting 35mpg in your Prius, then I would expect you would not even consider any car that doesn't have an EPA rating of 35mpg or above in the future.

 

The crazy part is that some of the people angry about their "poor" mileage or mileage drops during cold weather frequently pointing to some other car, usually a cheaper one... But, of course, that other car gets even worse mileage and in most cases can only achieve 35 mpg in the best case(s).

There's one notable person here (I won't name him ) who kept whining about his mileage drop and finally got rid of his 2010 Prius in favor of a car w/significantly lower mileage.

 

But it meets his expectations, and that's what really matters :_>

 

My wife's XTerra only has a 5% drop in mileage from 18 MPG to 17 in the winter, compared to my 10% drop 47 to 42 MPG. This does NOT mean we drive the XTerra more.

 

Of course not. Not only is XTerra's absolute fuel consumption worse to start with, so is its winter penalty.

Winter fuel consumption change per 100 miles (neglecting rounding):

Prius summer: 100/47 = 2.13 g
Prius winter: 100/42 = 2.38 g
Prius winter penalty: 0.25 gal/100 miles

XTerra summer: 100/18 = 5.56 g
XTerra winter: 100/17 = 5.88 g
XTerra winter penalty: 0.33 gal/100 miles

 

That right there is another reason I prefer the litres per hundred kilometer unit for fuel consumption that we use here.

 

If that’s the case your motor is running constantly , when it’s supposed to be off half the time , reply back for a solution if this is happening

 

May be your hybrid batteries are not working properly or their life has been over. Secondly make sure you do not drive your car at higher RPM by putting un necessary pressure on accelerator paddle to get high pick.

 

I suspect the poster has found a solution of one kind or another in the (almost) 8 years since this was posted.

Don't hold your breath waiting for a reply.