My G2 is getting really bad, REALLY bad fuel mileage recently. When I first got it about a month ago, I was getting about 40 MPG which I thought was kinda on the low side, but figured I still needed to learn how to drive the vehicle...coming from a VW diesel and 5-speed. I have done some work on it-spark plugs, PVC, air filter, new 12V battery-and now my MPG hovers around 29. I drive about 130 miles a day for work and that's why I bought this car, my truck is not that economical. With the mileage this car is getting though, it is almost beneficial to just drive my full-size pick up everyday. Would greatly appreciate any help and recommendations for this. Thank you!!
Your 40 mpg is a little on the low side, but not bad. Here's some fuelly stats: 2006 Toyota Prius MPG - Actual MPG from 294 2006 Toyota Prius owners But that drop's not good. More info would help. Where's that 130 mile daily driving, what speeds, what kind of roads, any steep grades, that sort of things. Especially speeds. Anything like a recent brake job, maybe causing drag? What tires are on it, specific make and model?
Check out this thread : Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new | PriusChat And some reading material : https://priuschat.com/attachments/why_dont_i_get_the_epa_mileage-pdf.7078/
Here is the usual list of things to look at: Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new (Duplicate, SFO beat me to it.)
I live in TN, just outside of Nashville and commute everyday to and from Nashille. It is all interstate driving, about 70-73 MPH. There a couple of hills, nothing huge though, for the most part, its pretty level. The make and model of the tires, unfortunately I do not know specific-I am at work and can't go check that right now. I noticed the decrease in MPG before I put new tires on it.
- Have you read This Thead Yet? Yes - What fuel economy are you getting and how are you determining fuel economy? (trip computer or manual calculations) both the trip computer and manual calculations-they normally are within a few miles of each other - What fuel economy are you expecting and why? I am expecting at least 40+ MPG because that is what most other's are getting - What are the approximate outside air temps? In TN, its been ranging between 30-80 - How long are your trips? 65 miles each way - How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving? It is mainly interstate driving- averaging no more than 75 MPH - What region/state are you in? (if you haven't set your location in your profile) TN - What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.) gentle hills - Is your oil overfilled? (i.e. above the full mark on the dipstick) No How old is your 12v battery? What is the voltage reading of your 12v battery after sitting over night? (Method Here) It is 1 week old Have you had your alignment checked? Any pulling or abnormal tire wear? No pulling - Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15). yes - What are your tire pressures? 30psi - Make, model, year, engine and transmission of previous car? (e.g. 08 Honda Civic Si 2.0L 4 cylinder, manual transmission) What did you actually get on the same trips/commute? (Please give us actual numbers, not EPA ratings.) I had an 03 Volkswagen Jetta 1.9L TDI with a manual trans-got about 45+ MPG on the same commute. - How are you trying to drive (e.g. trying to stay in electric only?) and how hard are you braking? I just let the car do its thing, even if I put it in "B" the gas engine still kicks on. I try not to break hard, driving in Nashville is hard not to. - Are you "warming up" the ICE (internal combustion engine) by letting it idle after powering on? Yes - Are you driving using D or B mode? D - HVAC settings? Are you using the heater, AC, auto mode, etc.? If using auto, what temp is it set to? I have been leaving it off, if I do turn it on, it has been the heat at 80...but I will turn that off about 30 mins into my trip. - If reporting a mileage drop, did anything significant change on your car (e.g. accident, hit a curb or big pothole throwing off alignment, oil change/other maintenance/repairs, changed tires or wheels, etc.) or your commute? I changed oil, spark plugs, air filter, PCV valve, new 12V battery...new radio, and new tires.
First thoughts: At your speeds of 70-75 mph, don't expect over 40 on a Gen2. A 12 year old car should have had the factory tires replaced long ago. What tire make and model are you on now? That is too low, pump them up to at least the figure on the door sill label. Many of us go higher. Don't use "B" except on very long mountain descents where there is risk of brake overheating.
I would up the tires to 40 PSI then lower if the ride feels too rough, rears 2 PSI under fronts so 40f/38r New tires get about 5 MPG less than old tires for various reasons for the first 5000 miles. If the new tires are not Low Rolling Resistance, expect a bigger drop if the old tires were LRR. Often 3 MPG for the life of the tire. My Gen 2 got 42 MPG when I drove 61 MPH a lot. The flatter it is, the better Cruise control does, the hillier it is the better you can do at coasting to crests and gently powering up going downhill.
I just put brand new tires on it...I read the question as the factory size tires and rims. I don't expect much over 40, but I think the mid to low 20's is a bit ridiculous. I will try to air them up more, I thought the recommended amount was 30psi. The only time I use B is in heavy traffic or going down a large grade hill.
I would be very happy with 42 MPG, on a good day, I have been averaging at most 29 MPG these last 2 weeks.
Would a battery conditioner help with the fuel mileage at all? Is it a beneficial thing to have for the car?
Yes, a HV battery reconditioning system could be beneficial (generally speaking). Since the vehicle is new to you, do you know if the HV battery is the factory original or otherwise? How many miles does this vehicle have now?
The guy I bought it from said that the Hybrid battery was just replaced shortly before I bought the car, but had no receipt for it. So I am not sure how true that is. The car has 246K on it.
sounds like you 'broke' something during the tune up. maybe go back and retrace your steps. 30 is incorrect for the tires, see the drivers door jamb. i don't think that's your problem though. any leaks around the air filter box after changing? what spark plugs did you install? did you check the gap?
If the car has a new rebuilt hybrid battery, it would still likely have a warranty- can you get more info from the seller? The name and location of the shop would probably be enough. If the previous owner just replaced a couple of battery modules via DIY, then there probably won't be a warranty. Your commute is ideal for good fuel economy. I drove a Scion with barn door aerodynamics with a 1.5 1NZ-FE engine (similar to yours) and would average 34 mpg on a similar 130 mile highway commute. IMO, your decline with fuel economy is not the result of maintenance, tires, etc...
I can go back and look at everything again. I didn't notice any leaks around the air box...then again I didn't really look for any either. I used the NGK iridium plugs,and was told they didn't need to be gapped, that they were already pre-gapped to the car. I believe they were gapped to 0.43 already though. I will add more air to the tires to see if that helps.
I will need to try and contact him and see if I can find out exactly where he got the battery from and check it out. I don't drive the car crazily...kinda hard to lol. I know a lot about cars, but this is my first experience with a Hybrid... so I'm not sure if it is something small I am over-looking. My last car was a VW diesel and I got this because I figured the mileage would be close to what I was getting before.
If you don't tell us the make/model/size of your new tires, we can't easily help you as they may be a major source of low MPG. JeffD
