Newbie with questions

Hi everyone! Well, I've had my 2010 Prius for about 6 months, and I love my car, though there are some issues that I have questions admit, and it's hard to find the right links to figue out my issues, so if y'all could help, that would be great.

First and most pressing is my sudden drop in MPG. I just filled up last night, and when I got in today, I noticed that my MPG was around 26, where normally I average between 37-41, depending on how much I'm babying her and milking EV mode, or just opening her up on Power mode. Usually the MPG display is at least a gallon or 2 higher tgan the actual mpg once I fill the tank and do the math.

So, I read online that it might be either the 12v getting bad, the spark plugs needing to be replaced, or the tire pressure needed to be adjusted. I usually fill my tire up once a week to 45psi (sidewall says 44), but this thread I found earlier said to lower the rear tires at least 2psi. So I did that and after driving another 30 miles, my mpg only went up to 35.

I would like to test the 12v, but my Prius is without a touchscreen, and the only info I can find is for touchscreen access...is there a way to test tge 12v without a touchscreen?

My second issue is my passenger side headlight. After I bought the car used, the passenger headlight went out after the first month. I bought brand new bulbs for both sides, but after installing them, I noticed that the passenger side was much dimmer then the drivers side. Then within the first two weeks, the drivers side bulb went out...I assumed that maybe it was just burning too hot. So, I switched tge still good passengerscside bulb into the drivers side, and put the original bulb that was still viable into the passengers side. Well guess what, the drivers side was still brighter...and then that one burned out the next week. I then assumed that the bulbs were old, because I bought them off ebay for a cheap price.

So, I tgen went to the local auto shop and bought brand new bulbs off the rack. Again, the passenger side was still dimmer. Well, those bulbs have been finde the past couple of months, but in the past few weeks I've noticed that the passenger side headlight is gathering condendation on the inside. Could it be that because of this condensation its what is causing tge socet to be weak on tgat side? And I bought a vrand new socket,just in case that's so, but is there any way to fix this issue workout sending $500 parts and labor to put in a whole new assembly at the dealership? Could it be a seal that needs adjusting?

Lastly, I'm sure some of you who own a 2010 have had the issue with paint chipping and flaking off of the edge of the roof just above the top of the windsheild...I've seen other 2010's around town with this same issue. I'm guessing it might be due to the pressure of the auromatic car wash brushes...is there any way to fix this or do something to prevent further flaking/rusting?

 

Thank you! She's got a bit over 153k at the moment. I can understand the dip in mpgs for winter, but this was literally an overnight decrease by at least 14mpg. That's pretty substantial. I just filled my tires when I filled the tank so it mashes no sense that my mpg would be that low, and the previous fill up had me at around 38mpg, but that's including me driving her hard that week and I hadn't filled her tires in almost 2 weeks. After filling the tires and discovering tge 26mog drop today, I let 2psi out of the rear tires, mms after 30 driving miles today, she's now at a little less than 37.

And now the passenger light is back on!???

 

Yes, I mentioned the headlight issue in my original post.

I have some records, but I don't know if those were done...I could call the dealership and see if the previous owner had those done or not.

How do I find your edit on 12v testing?

 

oh thanks, I see it now...didn't see it earlier on my phone.

 

I filled up that night before, and drove 20-something miles before going home, and noticed the mpg the next day. Today, I'm at a little over 100 miles on that same tank of gas, and the mpg at up to almost 38mpg...I hope it was the tire pressure after all...still going to buy a battery tester and make sure.

 

Thanks for your input, mmodem.

As far as I know, everything is original. When I first got the car, both headlights were actually at the same brightness level, and it was only after the first bulb went out that I noticed the difference. I plan on taking the assembly out as soon as possible and hitting it with a blow dryer to clear out the moisture, and add a silicone seal around the rim.

As for your MPG average, perhaps you and I are averaging it differently. Whenever I fill up the tank, I reset the trip odometer. That way, I have an idea of the average MPG I am getting overall for that particular tank, which as I said, averages between 37-41 give or take, depending on how 'm driving. If I am in a bad mood, agitated, or just stressed with shitty traffic, I put her in power mode and floor it...which ends up giving me lower mileage. When I'm conscious and relaxed, I ride her easy, keep my speed at or below the midpoint of the eco meter, and use EV whenever I'm in a reduced speed area, mostly going uphill in residential neighborhoods, etc. When I do that often on a tank, my MPG is usually around 40.

I'll check out the video, but I don't understand how I use more gas using electric mode...that just doesn't seem logical to me.

 

I understand that one of the ways to refill the battery is that the engine has to run...as well as while braking.
Can you explain the second mart of your comment? I didn't fully comprehend what you mean.

 

Thanks for the explanation, Steve.

So, I watched the video, and everything that he said is what I have been doing instinctively all along, with the exception of using EV while going uphill for short distances. So you're saying that it's better to use regular driving when going uphill, say for a block or two in a low speed area, rather than EV mode? The car uses more fuel when recharging after depleting the battery than would be used just driving normally? This is my first hybrid, so this is all new to me.

Also...according to Toyota, I should be getting 51 city/48 highway, but my average is around 40. Could this be because of the EV driving? Granted, I used AC in the summer, and run heat in the winter, so this takes a big chuck I would guess. Any other tips on running cabin temperature?

 

Okay it's starting to make sense, thanks.

It depends..lately I have been driving in Eco mode, but for a while I was running in Power a lot, because I noticed that it seemed to readout similar on the eco meter regardless of which I used, but power gave me better handling and acceleration.

 

Okay, I have no idea what "lcv, throttle body/maf cleaning, injectors and etc" are...can you elaborate on exactly what I would need to do? I want to make sure I am getting her serviced and updated to keep her running strong and maintaining a high resale value.

I have driven it like a hybrid on a whole tank, Steve...like I said, I have had it six months already...the highest MPG I've gotten on a full tank so far was around 42-43.

thanks for the other tips.

ummm...is that a good thing? LOL