Steve in reponse to your inquiry about mileage expectations/tecniques: (Originally posted on the Edmunds Camry Hybrid forum)

Much of this has been covered in the Prius and HH forums but since the TCH is new I thought I'd summarize what drivers might expect in this very interesting area.

First some oft-heard statements/myths:
you can refer to post # 2890 on the Hybrid Highlander by cdtrap wherein he summarized many points of misinformation. Not all apply to the TCH but enough do.

EPA Estimates / testing methodology
You can go to the EPA website to see how they do the testing but at present the tests are based on 30 y.o. assumptions. If you drive moderately you will approach/attain EPA values. Moderately doesn't mean poking along. Normal suburban driving near a mall or on a 40 miles per hour heavily travelled road will be the 'sweet spot' for your fuel economy. On New Years day on flat terrain in 55 deg weather with no wind ( must specify conditions ) I was able to attain a combined 65 mpg in my Prius while out for a 'Sunday drive' looking for a specific store at about 35 miles per hour on average.

Highway driving at 55 seems to be the most efficient. For the new TCH one should attain just about 37 mpg ( EPA estimate ) at this speed. For every 10 miles per hour faster above 55 you will lose FE; e.g. at about 65 you may show a FE of ~33 mpg; at 75 miles per hour you may show a FE of under 30 mpg. Why? Increased drag kills the FE for all vehicles above 75 miles per hour. Also in keeping this speed you are riding the ICE almost all the time not giving it a chance to turn off.

Turning off/turning down the ICE
This is the one of the most ingenious traits of the HSD system and it's mainly dependent on the driver. As the controller of input ( your brain, foot and pedal ), the driver can induce the ICE to turn off/down while driving during which time little or no fuel is burned. Pretty basic. As noted above if you are racing at 75 miles per hour nearly all the time you are just driving an ICE 2.4L Camry. Drag and driver input will keep your FE low. But if you have to drive like this due to conditions then you have to. Be safe.

Using 'pulse and glide' in any situation whether 65 miles per hour on the highway or 25 miles per hour in the city can turn off or turn down the ICE and allow you to save fuel. Use it. It's easy and causes no disruptions at all if done correctly.

If however you have a choice of routes and the time then consider not taking the highway. What many have found is that giving up the bustle of highway driving by using suburban roads at more moderate speeds is a) more relaxing and b) more fuel efficient.

Anticipation:
This is linked to driver input. If you are in a situation such as a suburban road or highway where you see a blockage or traffic light up ahead where you will likely slow or stop then let off the pedal as early as possible while still being safe. When you let off the pedal you turn off the ICE and 'glide' to a stop ( not burning any fuel ). This also saves wear on the breaks and is in fact more relaxing. Stipulation: you do have to use the brakes to come to a dead stop.. use common sense.

Weather conditions:
Fortuitiously the TCH is coming now when the weather is mild. During Winter months expect the FE to deteriorate by about 10%. The same is true of rough weather at other times ( think riding a bike in windy conditions ). EPA weather conditions: tests done in a laboratory at ~72 deg with a fully warmed up engine.

Your personal real world FE rating:
One of the most misunderstood statements regarding the EPA FE ratings is the Combined rating. The EPA is not a rigorous scientific body. It's results have to be utilized in a political environment. Thus in the case of the Prius it's ratings are 60 City - 51 Highway - 55 Combined. The EPA just makes a 55/45 assumption about the 'typical' driver's mix of driving. But what if you are not typical? My own is 85% highway @ 60 miles per hour and 15% 'city' @ 40 miles per hour. To be exact one should take the weighted average in order to get a correct 'combined' value. Mine is 52.5 mpg in EPA weather condtions.

Short trips kill FE for all vehicles.
If your normal driving pattern is short hops either to work or around town then the ICE/exhaust system never has a chance to get up to it's most efficient temperature. Everytime you stop and turn off the motor then the engine cools and everything must be started again. In this case you are driving a normal ICE 4c Camry in the most disadvantageous City conditions. Be honest with yourself in the type of driving you might be doing.

Now combine all these variables into a single algorithm describing your personal driving. It can be done.

For example:
Winter driving against a strong northerly headwind at 75 miles per hour on a just recently plowed roadway ( Minn commute? ).
Your fuel economy might be in the 30 mpg range or lower.

Take a Sunday drive looking as houses cruising through various neighborhoods now in springtime. You might attain 45 mpg!

Lifetime fuel usage: 2.1 GPC ( 1.99 recent )