I think my mileage success is related to having hybrid-friendly driving patterns and also to good driving technique. This 2000 miles included about 75% city driving and 25% highway - freeway driving. I use the cheapest, lowest octane gasoline that they sell.
My work commute is about 20 minutes on country and city roads with a maximal speed limit of 55 mph. I only have a few stop signs and stoplights so I don’t have a lot of stop and go driving. I rarely need to take 5-10 minute trips, which reduces mileage considerably. My usual 20 min commute is ideal for getting the battery charged up and then being able to maximize the use of the electric motors for the last 10 min at the end of the ride.
My driving technique is quite different now than it was in the past with non-hybrid vehicles. You definitely have to earn good mileage with a hybrid. The dealers won’t tell you this.
For example, I almost always have the energy screen on and am conscience of maximizing efficiency. I would guess that I am able to spend about 15-20% of the time running entirely on the battery system (with 99 mpg on the monitor). I always try to run the battery down as far as possible at the end of every trip. My goal is to get the battery charge indicator down to 2 bars (the 2 purple bars) when I park the vehicle. When you restart the vehicle the next time, the engine is going to run anyway for the first 5 minutes so it might as well be charging the battery also. I can usually get 1-2 free miles at the end of every trip by forcing it onto the battery system as much as possible before I park the vehicle.
I also just try to drive the speed limit as much as possible. Anything over 65 mph is a mileage killer. I live in central Wisconsin so the traffic is usually pretty light so I rarely need to speed just to keep up with traffic. I also rarely have anyone behind me on my routes (if I do, I increase my speed to about 5 mph over the speed limit). Driving the speed limit is a big change from how I drove in the past. From a practical standpoint though, on any trip under 2 hours, I only spend a few extra minutes and it makes a dramatic difference in mileage.
This summer, I only needed to use the air conditioner for a few days (fairly cool summer in WI). The AC reduces mileage quite a bit. On hills, I also try not to use the cruise control. It reduces mileage when the engine revs up to maintain speed on the uphill and then doesn’t take maximal advantage of the downhill. At stoplights, I accelerate at a normal, moderate pace up to speed and then try to get on the battery as soon as possible. I don’t do any of the more advanced “hypermiling” techniques – pulsing, etc..
There are a couple advantages to “hybrid-friendly driving” that I would have never anticipated. First of all there is the fun factor. It is kind of fun to try to manipulate the car to maximize efficiency. It makes driving more interesting for me to watch the monitor and try to maximize the time I spend on the battery.
I also am much more relaxed driving a hybrid. I use to be the aggressive driver – trying to get there as fast as possible, pushing the speed limit to the limit, aggressively passing slower vehicles, fast starts from every traffic light, trying to always be in the fastest lane, etc.. Now I have a much more relaxed attitude about driving. Maybe I get there a few minutes later but I don’t care anymore. I have a fast paced, hectic job. Driving can actually be relaxing. It took a hybrid to teach me this.
The bottom line is that it is definitely possible to get very good mileage with the Rx400h is you drive it properly and if you have hybrid-friendly driving routes. Knowing what I know now, I would not buy another hybrid if I spent most of my time on the freeway. I would also not buy a hybrid for my wife because she wouldn’t be interested in driving it properly. I bet the dealers get lots of complaints about poor mileage from people that haven’t figured this out. Even for me, the financial payback for the hybrid is pretty long with current gas prices. My mileage also drops to about 26-27 mpg for about 3-4 months in the Wisconsin winters. I will be very satisfied though with the vehicle if it remains dependable and if the batteries last 10 years or so.
