Hello Everyone, just like to share few findings about estimated cruising range on display when I fill up. I think that this forum is really helpful, for example I found out that after Gas gage get to needle you can still drive 60-80 miles, I did on the freeway 60 miles.
But what was interesting, that as I'm trying to learn how to drive more fuel efficiently my cruising range was dropping every time I fill up. Last week when I filled up it showed 436 miles, I was pissed. Then I decided to disconnect battery overnight, sure thing when I started the car next morning it showed 535 miles. Basically I was doing everything right but by driving on near empty tank all the time the computer is trying to make me fill up sooner. So my suggestion is disconnect the negative battery overnight at lease ones in 3 months, I think it also resets and let all the sensors to rest for one night.
Happy driving. Tim

Are you topping the tank off? There may be some issue with topping the tank off keeping the car from accurately knowing how much gas you had for the tank, so it won't improve your cruise range for future tanks. I've stopped topping off (which is actually bad anyway), and cruise range is fine. But it still takes a little time for the car to learn. I don't think disconnecting anything should be necessary for the car to figure things out as long as you're not overfilling the tank.

I never topped off in any of my previous cars, its bad for environment. I think because of me driving till the tank is almost empty has something to do with that. Let me tell you about my habits, I fill up at the tear 1 gas company Chevron, Shell, 76. I never mix 2 brands, fill up Premium ONLY in California it is 91. I fill up but never topped off. I put Chevron Fuel cleaner Techron every 3k miles; I switched to synthetic Mobil one 5w20 oil after 10k. I drive mostly freeway and not much in the city. I use seat heaters a lot, my wife hates when I'm driving in E mode, it’s too slow for her she wants to get out of the car and walk faster. I still believe disconnecting battery is good idea.
Thanks

Everything I've heard says that using a higher grade of gasoline than what your car genuinely needs is a waste--that the higher grades are really just to eliminate knocking, so if you run well on regular you shouldn't bother with anything higher grade. I'm not an expert and I don't remember the specifics, but I'm sure someone in here will have more info.

But as for running till almost empty, I can't quite believe that would be interfering with the car's cruising range calculations--or something like this wouldn't be possible....

I have to agree Chestr. Premium gas is for high performance engines that require 93 octane. The majority of new cars.......the TCH being one of them only require 87 octane. If the owners manual says to use 87 octane fuel, then that's all the engine requires. Just think of the extra money your spending on fuel filling up with premium gas when all you really need is regular unleaded. Has to put a big dent in the fuel mileage savings of having a hybrid!!! I have NEVER purchased 93 octane gas in over 27 years of driving and never noticed any performance issues.

I take it you don't have a NAV or you don't care about loosing all your Audio presets. No thanks I'll just fill up a day early.

About the presets you are right; the phone book on the NAV is still good.

About the mentioned above that the engine don’t need better gas I don’t agree, because of the constant start and stop the engine will run better over the years to come, as well as synthetic oil helps. I remembered that in the manual on the back its states that recommended is unleaded 87 but (tested with 91) why?

I don't know why your range goes down but mine goes up and down depending upon how well I did on the previous tank. My best range was 690 miles and my most recent was 650 due to the colder weather.

I'm not sure why they would test with 91 octane. All i know is that i have had a number of vehicles from an SUV to this 2007 TCH and i have never had any problems with 87 octane fuel over many years of driving in different parts of the US and in Germany. I'm not sure why it would be tested with 91 octane. I do know that i have heard MANY times on numerous programs and have verified it myself over 25+ years of driving that 87 octane is all MOST vehicles will ever need. Maybe in some high altitude places (above 5000ft) might be an instance to use a higher octane fuel.

H20 Doctor is correct. The ECU predicted miles to empty after a fillup is based on calculated mpg over time, so that number can vary from tank to tank. Filling at 1/2 empty vs near empty should have no real bearing IMO.

I disagree with the requirement of 91 or higher octane. ALL my vehicles, including my 1972 VW super beetle up to the 08 FEH, use 87 octane. Higher octane is ONLY required for very high compression, high performance vehicles. Lets see - hybrid, small engine by design and desire, don't fit the 'high performance' category. Higher octane will certainly not harm the car, but it's really not necessary.