If you were trying to keep it in EV mode then the charge power meter will go down until the engine kicks in and raises it up to the middle. Hovering in the middle is not unusual, however the NAh really likes to be driven like a normal car and the meter usually stays above the middle if you drive without thinking about the hybrid.

I drove it today at lunch noticed the reduced regen on the brakes. That stinks.

In another post, I thought someone said that FE goes down when you drop below a half tank. Is that right?

Some of this stuff is counterintuitive. I would have thought FE might increase due to lower weight. Then I also thought regen would have been more efficient in stop-&-go traffic from using the brakes more often.

I'm glad I came here and asked these questions.

Not that I've ever seen. My FE seems to be fairly consistent throughout the tank, if the driving pattern is the same.

I assume you saw reduced regen braking because of mid-day heat?

Stop and go traffic is never kind to your fuel mileage; you never recover all of the braking energy. Long stops in hot weather (with the AC load) are even worse. Steady driving is better.

But hybrids suffer a lot less in stop and go driving than conventional cars, because they can recapture at least some of the braking energy, and because they don't waste gas on idling. So while heavy traffic won't help your absolute mileage numbers, it will actually give you a bigger relative advantage over a conventional car - because the conventional engine will do so much worse.

Which is why hybrid taxi cabs make so much sense.

Oh, and a word of explanation about sudden braking and its effect on regen:

When you have to stomp on the brakes, then the conventional friction brakes do most of the work (they're still the most effective way to stop a car quickly, short of running into a wall) - but that means a lot of energy is lost to friction (as heat). When you brake more slowly, the regen braking (using one of the electric motors as a generator) does most of the work, which not only recaptures some of that energy, but also saves wear and tear on the brake pads.

Thats the one thing I don't like about the NAH and just flat out makes me want to have a button where I can tell it what to do :-) I have a long hill right before I get home and while climbing my battery stays at 3/4 full. Then in the morning I start going down, the baterry gets to 100% and the engine keeps running cuz the car is still too cold... total waste of energy :-(

Now what would be really smart is for hybrid vehicles with nav systems to take advantage of the GPS and your route and optimize the electric usage depending on the elevation changes of your route! Too bad I don't design these systems...

If you're curious about the magic >42 miles per hour number where the ICE needs to spin (at least on the Prius), see http://eahart.com/prius/psd/. You'll see why. I don't know the RPM limits on MG1 and MG2 in the NAH, but apparently the 42 miles per hour is also the magic number on the NAH.

Unfortunately, I'm not aware of anyone having done similar work as this guy on the NAH (http://www.vassfamily.net/ToyotaPrius/CAN/cindex.html and http://www.vassfamily.net/ToyotaPriu...omeasures.html). CAN-view (http://hybridinterfaces.ca/disppars.html) isn't listed at compatible w/NAH either. It'd be interesting to take readings and see what's really going on under the hood.

06 Toyota Prius, 04 Nissan 350Z; mom has 07 NAH

I'm think an electric block heater is the solution to your morning issue.

Hand calculated numbers, not trip computer data.

have a link to where you can purchase the block heater?

I just ordered one of the Nissan engine block heaters that are pre-installed in Canadian Altimas. The part# is 110016P700, and the cord for it is part# 110016P700CS. Ordered it from a Canadian dealer who is shipping it to me. Total cost is $80CAN.

Installation, on the other-hand, was quoted by my dealer at $180 plus coolant. Ouch.

I got mine from TransCanada Nissan

Hand calculated numbers, not trip computer data.

thanks for the info!

and i just found you on nissanclub