I've had my HiHi (which I love and will drive until I or it dies) but I cannot get more than 23mpg. In the beginning I thought I just needed to learn how to drive it, now I am not so sure. I've had it for 4 months and put 2300 miles on it. I glide for LOOOOOOOOOOOONG amounts of time without touching the gas. I PnG as much as possible. My meter says I am in the 30-60mpg range more often than not, but when I do the math at the pump, I am not making it.

Any thoughts? I am concerned there may be something wrong with the computer. Before I drove off the lot, my dealer cranked the key with the car in stealth mode to show me that a valet could not hurt it if the ICE was off. Did he screw something up? Am I just being neurotic?

 

I offer this check list to anyone initially questioning their mileage:

Check the back/trunk. Are you carrying weight that isn't really necessary? (I state this because my wife loaded the trunk of my HCH with diet Coke when it was on sale. 16 twelve packs equaled about 128 pounds of extra weight.)

Check the air pressure of the tires. Whether you subscribe to increasing the air pressure or not, having mismatched pressures is one thing most people agree can tank your mileage. The front tires should be equal and the back tires equal. They should be in the generally recommended pressure set by the manufacturer of the car.

Lastly, check to make sure that there are no obstructions to the engine air intake ductwork. Sometimes, debris can fly into the grill and block this intake.

Remember that you are still "breaking in" your car. Most people see a bump in mileage at the 3-5k mile mark.

Good luck.

 

Is it true that you do no damage by "starting the car" after it is already started? I would think its much like turning a light switch on and off, but am not sure. I park in a parking garage frequently, and this happens all the time, despite my preemptive explanation to the attendants.

 

There are a few things working against you here. First, it is winter over most of the U.S. and as such cold weather, denser air, winter forumlation of gas and the the conditions of your commute all might be limiting your FE. There are very few of these items that you can control. So, I seriously recommend that you make sure that your tire pressure matches the spec that is on the vehical cert sticker on the driver's side "B" pillar.

Break-in is a reality with these vehicles. I figure that by the time you crack over 5k you will see some better numbers. Second, I'm not sure which trim package you have on your Highlander, and I'm not real familar with what mileage tracking there is on the Highlander, but if you have an onboard FE average calculator, compare that number to anything you calculate. You will be off by a few MPG almost all the time. However, an onboard FE calculator is much more accurate than your hand calculations because the vehicle is calculating FE based upon actual metered fuel. You calculate FE by comparing how many gallons you used between mileage points. The problem with that calculation is that each fillup is not necessarily going to fill the fuel tank to the exact same level each time you fill up. So, there is inherant variability in that calculation.

 

I find that what really kills milage are short trips. The engine on the Prius needs at least several minutes to warm up during which time your mpg is "hosed". This repeats everytime you restart the engine. I would imagine this to be a lot worse in a V6 car. So what type of driving do you do?

 

Short trips definitely don't help, and from your months/miles you're putting on about half the miles we have since taking delivery end of July (passed 5K last week, service next Friday). Our work/class commute is a little over a mile, and the engine runs now that it's cold most of the trip to get the system up to temperature, if it ever does. So the engine is running at low efficiency and the batteries/motor don't kick in. Take a long trip and our mileage gets better, close to summer. We're doing about 24-25 compared to about 27 during warmer months where we were short hopping less (walk to work sometimes) and making longer trips to get organic produce (been too busy to enter for a while, keep a running log in the car). Nothing scientific but from reading other boards some actually do better on mileage by extending the drive a little so the engine heats, the battery charges and gets used and the vehicle gets to run without the engine some of the time. Don't have the time to try it though...

As far as starting in stealth mode goes, remember that the HH is a drive by wire vehicle - there aren't the mechanical functions in it that there in a standard ICE vehicle. You can't hit the key on an ICE since it activates the starter that kicks a gear into the flywheel and if it clashes, broken gear teeth (unengineering explanation). There is no starter on the HH, it uses one of the motors that is connected through the CVT the same as the other bigger drive motor and the ICE and the various gears are all designed to be controlled by the computer. I suspect but don't know for sure that the HH knows it's already on and running and simply ignores any more hits on the starter position. While the HH to the driver is just like any other conventional vehicle, the functions are managed by computers and electronics to much greater extent. - John

 

It wasnt until I actually bought my Prius last Nov that I realized - Eureka! - what the basic benefit of the HSD system was.


Background: I sell Toyota's and have specialized in the Hybrids since they were introduced here in 2001. I've read a lot here and elsewhere but actually having seat time in them is so much more usefull to understanding the concept.

Disclaimer: I am not an automotive engineer but I do have a math/physics background. I will defer to anyone who is actively involved in the field.

All hybrids are basically ICE vehicles. Most of the time they are just like any other vehicle in it's class. an HH is just the same as an ICE HL most of the time! The benefit of the HSD system is that it allows the ICE to shutdown frequently thereby burning no fuel. The more a driver can create times for the ICE to shutdown the less fuel will be used. It's perfectly obvious.. but

A) in cold weather the ICE has to run more because it has more work to do ( heat the cabin, the engine fluids and the catalytic converter );
B) in accelerating the ICE is running nearly all the time;
C) n short trips, see A), the ICE is running for the entire time;
D) during high-speed driving you run into significantly increased aerodynamic resistance which makes the ICE work harder.

In all four of the situations above you are essentially driving a 3.3L ICE Highlander or in the case of the autos a 1.5L Prius or soon a 2.4L Camry.

Our goal as drivers is to maximize frequency of times and therefore the amount of time that the ICE's can shutdown.

Some situations are beyond our control. If you must go to pick up the children at school and return home right away, this short trip will be on the ICE only.

 

I asked this question at the Madison Hybrid Users meeting yesterday, because it bothers me when my DD or DSIL turn the key without looking for the "ready" light.

Politely answered (and no one laughed): Not to worry about dis-owning the DSIL. The HiHy doesn't have a "starter" in the usual sense. When you turn the key it is a message to the computer to start the battery. Turning the key again doesn't re-start it!

HTH. And I am sure others will jump in with more info.
Lots to learn! But fun! ANd what a GREAT GROUP in Madison!
EMO