Horrid Gas Mileage?

18-19 is far too low. I'd reset the average mpg, fill tires to 40 psi and check the oil. Drive it on the highway and some city. See what it says. Best of luck! Feel free to ask me any questions

 

Make sure they used 0w-20 as well. Make doubly sure. Apparently some shops can get a little shady and sub cheaper, semi-synthetic oil while charging you the same rate for full synthetic.

 

It's going to be hard to tell if they used 0w20 or not just by eyeballing it. I'm really not sure how you'd tell for sure, other than taking it to a shop you trust.

 

You have a Gen 2 model, the factory suggests 5w-30 weight oil, not 0-20, and unless they overfilled the oil (Check your dipstick) oil should not be your problem, a failing 12 volt battery or a failing hybrid battery are among the usual suspects.

 

Thanks for correcting me. I didn't even look to see what Gen he was.

 

I forgot one thing you have rubber bladder in your gas tank, so in winter the size of your gas tank varies, it will take a few fillips to determine your gas mileage.

 

welcome! how many miles on her? when you own a 10 year old car, it's important to know how to check the oil level and the tyres pressure.
and with a prius, a knowledge of the 12 volt is also helpful.
i would check/clean/replace the engine air filter.
and don't rely on chain oil places for anything
all the best!

 

Sometimes old change places overfill the oil. That's why I would check. Still something is very wrong. What type of driving do you do? Also do you ever watch the behavior of the Hybrid Battery?

 

I thought I read somewhere that there was an addendum to the owners manual changing the recommended Gen 2 oil viscosity to 0W-20 but the electronic version I downloaded from Toyota still says 5W-30.

That said, I don't think 5W-30 would make that much difference. I wonder if they overfilled it (many shops do and that's one of several reasons I change my own). And maybe they did put in the wrong oil AND overfilled it. This sounds like it could be a combination of oil, low tires, dirt cabin air filter, and/or other things piling up.

 

this is how i check my 12v health. there are many methods, and threads here with descriptions.

1) it's a good idea to know how old it is. if you don't know the service history, there is a date code on top.
2) buy a digital multi meter. $10. -$20. on amazon and useful for many things.
3) pop the hood at the end of the day, when you're done driving.
4) in the morning, without opening any doors, open the hood and find the jump point described in the manual.
5) measure the voltage. 12.4 or better is acceptable. any lower, and it's time to start thinking about a replacement.
6) an auto parts store can do a load test on the battery. if you're having issues, a voltage check may not be enough.
because it is in the hatch, the prius battery is small, and doesn't take kindly to being drained.
it is only used to boot the computers and close relays. if it is weak, the computers get fussy and can display a lot of error messages.
a bad battery can also drain the hybrid battery trying to keep it charged. in turn, the engine must run more to charge the hybrid battery, reducing mpg's. that's why it's important to keep an eye on it.

 

How many miles did you drive to get this number? And what was the average length of your trips? Short trips can produce really bad numbers due to the fuel being consumed for initial climate control instead of movement. If your trips are under 10 miles, and especially if they're under five, this could be a major issue. That said, compare apples to apples. If the same trip, in about the same time and temperature conditions, sees a major drop, then something's wrong. But a 3 mile trip in the winter is going to be bad, no getting around that. Other than turning the heater off.

 

It wouldn't surprise me if the Qwicki Oil place didn't put the correct weight oil in AND/OR use synthetic oil. Go bak to QO and insist they VERIFY they put in the correct stuff. All the other suggestions about overfilling the oil, tire pressures, 12V battery, and etc. are good things to check as well. If the 12V battery is the original (check top/side of batt for a date sticker/tag), it is very likely it needs changed. Please let us know what happens. Best wishes!

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I get about 37 to 40.3 miles per gallon on short trips like 11 miles.Two weeks ago I took a 47 mile one way trip stop and go traffic and produced 53 miles per gallon . I have a 2010 Prius 4 so it looks like these cars produce better gas milage on longer trips

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I think cold weather ICE warmup is affecting your short trip mileage.

 

How would I do number 4? On my car the hood release is inside the car.

 

Do number three first.

 

Oops!
I missed that. I wondered about that but figured there was a more secure way.
Thanks.