How badly can the 12v batter lower mpg?

sounds fine and wouldn't affect mpg. if you recently got the car, how do you really know anything at all about mpg's?

 

too early to panic. put a couple tanks in, calculate each tank manually, and if you're unhappy, come back and fill in the sticky on mpg's, and we'll try to sort you out. all the best!

 

@Dain Hill

Just for grins, what speeds were you driving on this road trip? Were the roads flat, hilly, mountainous? Lastly what kind of MPG do you think you got and how did you measure it?

Those voltages look OK to me by the way.

Best of luck to you and "Welcome to Prius Chat"!

 

That sounds about right for 75 MPH. I have found the sweet spot to be 50 - 60. The ICE was probably running all the time. Also for some reason cruise control decreases MPG. Check the pressure of your tires. Most folks run them 5 PSI above the door sticker when cold.

Posted via the PriusChat mobile app.

 

Based on your reply above, I think your MPG is SPOT ON! Prius doesn't give the best MPG when trucking down the super slab. It shines the best when driven around town. Google "Prius Pulse and Glide" for one of the hypermile tricks. Don't do that if you are in traffic though, it can cause road rage. Not everyone like a Prius for some reason.

On our Gen II, the best I ever got was just over 60 MPG. My lifetime average for the time I drove it was around 48 if I recall correctly. Could be doing better with ours, but the 17" tires drag down the numbers a little bit.

Enjoy your new to you Prius and "Best of luck to you"!

 

Agreed for sure on the tire pressure. Try 42 front, and 40 rear. A little rough, but will help to bring the numbers up. Mobil 1 Oil will also help too!.

 

you need to find a new service place.

 

A PCV valve exists on the Gen2s.

Engine and Inverter cooling loop for the Prius is a simple drain and fill. These two loops are independent of each other. You could drain/fill the engine w/o affecting the engine loop and visa versa, drain/fill the inverter w/o affecting the engine loop. Elimination of air pockets is an absolute.

+1

 

Did you mean "You could drain/fill the engine without affecting the inverter loop"?

 

Yes. Thanks for the correction. The radiator has two separate cooling loops: engine and hybrid/inverter.


Pictured is the Hybrid/Inverter loop.



Now how likely would a rational person, NOT do a drain/fill on the Inverter loop, if the Engine Loop is getting drained/filled? Such a person would have to be really cheap to not do so, and must have lots of free time on their hands.

The car is up. You or a paid mechanic is draining/filling the engine loop. A few minutes more, and a few dollars more, the Inverter Loop can be drained/filled at the same time. To do the Inverter later will cost you more time and money.

 

When I bought my '05 Prius 4 months ago, I noticed someone had used orange coolant in the engine loop. Lacking time and the space I took it to the stealership for a drain and refill. Having 194K miles, I asked about doing the invertor loop at the same time. Was told they had to charge both book times because they were 2 different systems. Service writer couldn't find a single time for both jobs. Needless to say, I paid for the engine loop only and will be doing the invertor loop myself soon.

 

Newbie question: How do I measure the voltage on the 12V battery?

 

You use a digital (or analogue) multimeter (DMM) set to the 20 or 200 V (DC) setting. You can then directly measure the battery in the back RH cubby or use the jump point in the engine bay, your own manual with show you where exactly both are located.

You want to measure and record three voltages and report back here with them. they are:

1. First thing in the morning after the car has been off overnight. Note the voltage
2. Make the car IG-ON (Press the On button twice with your foot OFF the brake). Note the voltage
3. Make the car READY. (Press the Power one more time with your foot ON the brake) Note the voltage.

hope this helps.

 

The US third gen maintenance schedule (fwiw) spec's a significantly longer mileage/time interval, inverter vs engine coolant interval:



I'm not sure about second gen schedule, haven't looked it up. Still, I doubt either job is trivial/quick, there's been a fair bit of discussion about problems getting air pockets out, especially on the second gen. In other words, it's not just "oh while you're at it", one more drain tap that needs opening.

I believe third gen coolant changes are easier, especially judging from @NutzAboutBolts videos.

FWIW, the Canadian 3rd gen does not have a different interval for engine and inverter coolant change.

 

I had moisture in a sealed unit headlight in another vehicle (a BMW). I used a hair-dryer and a paper towel cardboard tube to remove it. I took out the bulbs and used the hair-dryer blowing into the cardboard tube which was tapered to fit into the main headlight bulb hole. The air blew through the headlight and out the parking light hole. I used a warm setting (not hot) and in 5 minutes the moisture was gone. When finished make sure the rubber boots around the bulbs are properly seated as that's the place moisture often enters the assembly.

You might try this before spending $350 or so.