Poor Fuel Milage

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!!

 

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.

 

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?

 

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.

 

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.

 

Damn...How did you know?