Just got back from a weekend on Cape Cod. It is an 82 mile trip (one way) for us. My wife drove the NAH, it was a typical heavy traffic Memorial day weekend Friday, but speeds averaged about 60 to 65mph. 44.0 mpg according to the dash readout! One thing to note, when I filled the tank before the trip I mistakenly hit the wrong selection at the Mobil station and put 93 octane in it. When I noticed my mistake I stopped at 11 gallons (the car already had 1/4 tank of gas before the fill-up). I don't know now if this car really likes premium fuel, or we just got really lucky, but we were just "going with the flow" on the highway.

 

I'd put my money on "going with the flow". Lately, I've dropped my highway speed from 72mph down to about 67mph and we've seen our FEH go from 27mpg up to 30mpg. The numbers don't look like a big jump, but percentage wise it is pretty significant.

 

Average it with the other way too :-) If there is an elevation change in your favor the car could easily get that kind of mileage. I went up to Palm Springs over the weekend and on the way up (~143 miles) I got 32 mpg. On the way down I reset it, and got 48mpg (~145 miles) (and no, I have no idea where the extra 2 miles came from O__o, its the same route!)

 

The route is basically flat. We live at 300ft ASL and you hit the coastal plains in a few miles which averages 100ft ASL. So we do lose 200ft. Problem is we used the car all weekend running around. The average dropped to just under 40, then went back up to 42 on the trip back. I'm just perplexed at the fact that the hwy mileage was so high, it usually kills my average. I'm still on the same tank and sitting at 39.6 right now.

 

Possible explanation could be a tailwind. A steady 20mph tailwind would have the same effect as driving 45 miles per hour instead of 65 miles per hour. Of course in order to explain your mileage you'd need a tailwind both ways but living in NE that's not out of the question with the weather in the spring - a warm west wind one day and then a cold east wind the next.

 

My NAH is getting crap MPG

so far with 10,000 miles on her its avg. 28.15 - 28.7 per tank very very very consistantly.

took her to colorado and got 30 hwy but in the city its right above 28mpg every single tank.

I coast to stops lightly using brakes to regen battery , on downhill areas I get to 40 mph then hold in EV mode for 1/2 mile to 1 mile , don't push the engine past the first mark on the power indicator , try and keep to speed limits and tires at max pressure.

not sure what to do

going to try a thinner oil this next oil change.


whats the sweet spot (speed wise) on this car for mpg??

 

Iboom...

I don't think you should have to try that hard. If I drive like a total ahole I get 33mpg. When I start to get conservative it goes up from there. And when I'm in "mileage mode" I can break 40. This is in "suburban" traffic. On the highway I get into one of 2 modes. 1. get there fast (80mph) , and 2. Lay back (65-70mph) The difference is 33mpg vs. 36 or higher. (I don't know how my wife got that 44mpg).

So IMO something is slowing down your particular car. Do you carry dead weight? What exactly was the oil (weight and type) they put in your car? I change my own oil and use Mobil-1 0W-20. Do you run the A/C all the time? What is your typical state of battery charge (blue meter)? Does the engine shut down often? (I know, what is often?)

Recently I found the "First responder's guide" for the NAH (see post in this section). I learned a few things about our cars I did not know. The hybrid battery system state is EVERYTHING. It has 3 converters which run off of it. One 245V to 12V system to charge the 12V battery. One 245V to 42V converter to run the power steering. and one 245V DC to 600V+ AC 3 phase to run the drive motor (M2) and the A/C . So something as trivial as a bad 12V battery will cause the M1 generator to work harder to keep the hybrid battery up, to keep the 12V battery in spec.

One other thought would be your altitude. Do you know of any other hybrid owners in your area? Are they experiencing anything similar?

 

Don't know what could be causing that; I haven't seen numbers that low except in the dead of winter.

The 'sweet spot' (as far as I've been able to determine) is in the 30-45 mph range, in mild weather (no heater or AC), and a long enough trip that the warmup period doesn't kill the average (10 miles or more). This morning, on a 45 mile trip, I got 51.9 mpg (by the computer - probably about 48 in reality).

If you can't get at least 40 mpg under similar conditions on suburban or country roads, then there may really be something wrong with your system. If you reset the trip computer after each refueling, then the best time to test this is after a refueling.

Another possibility is that your computer reads low (unlike most, which seem to read high).

 

Steve, I don't see a log for you. Do you keep track of your mpg, trips etc...?
Are there any times when your mileage is up or changes drastically mid tank?

 

Victor, I do have a car in the database, but I didn't know about this site when I first purchased my car, so it's not quite up to date. I reset my mpg computer when I fill up like most do. I don't really keep great records. We have a camp in Maine, and at any given time on a tank of gas, a 3 hour hwy trip may be thrown in, that's one way, (175 mi.). Last time I filled up was in Maine, I only got 33.4mpg on the trip home as we were in a hurry to meet up for Father's day. I'm still on the same tank, but now the average is up close to 37mpg. If the car stayed in town, I would be past 40. But as you know, the range on these tanks is so awesome, it would be difficult to stay in one driving venue for the entire period.

Last time my mileage started to change drastically was during the 4 day heat wave here. I was averaging over 41, then I started using the A/C heavily and ended up around 38.