Getting the Most Out of the Toyota Prius: Driving Tips

113 messages, Last post on Sep 23, 2009 at 7:16 AM

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What is this discussion about? Toyota Prius, Hybrid Cars, Hatchback

Do you have a technique for getting the most out of your Prius? Share it here!

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#54 of 113 Re: Prius always starts on gas engine [pathstar1] by jana6 Jul 13, 2007 (8:36 am)
Replying to: pathstar1 (Jul 05, 2007 7:31 am) Could you explain what you mean by pulse and glide? I'm assuming it means speed up and then lift your foot off the gas peddle completely but I may be wrong. If that's the case, how do you do that on the freeway--constantly speeding up over the speedlimit and then slowing down to what????? Also, would you recommend using the cruise control more to get better gas mileage or not? Thanks, Jana6 Replies to this message: pathstar1 (Jul 13, 2007 11:53 am) jana6 (Jul 16, 2007 10:23 am) pathstar1 (Jul 16, 2007 5:56 pm)
#55 of 113 Re: Prius always starts on gas engine [jana6] by pathstar1 Jul 13, 2007 (11:53 am)
Replying to: jana6 (Jul 13, 2007 8:36 am) Pulse and glide: You speed up to some "high speed" and then gradually release the accelerator until you get no arrows on the MFD. You are then coasting. You allow the car to coast down to a lower speed, then repeat. This is easy below about 42 MPH (called "stealth mode" - the engine shuts off for you), but takes a lot of feel above (called "warp stealth mode"). Above 42 MPH (66 km/hr) the engine will not shut down - that is, it will spin, but if you are in warp stealth, there will be no fuel injected into it. It is spun by MG2, as I recall and you will again see no arrows on the MFD. The gap in the accelerator travel where this happens is VERY narrow. For simple stealth it's wide and easy to attain. If you want to learn this, a low traffic secondary road is the best place. I recommend thin soled shoes that you can feel through and flex with your foot. Helps a lot. I wouldn't recommend doing this if there is -any- traffic. It works best on lonely secondary roads. It is mostly for those mileage fanatics who like to brag about how high their mileage is, but you can use it from time to time when conditions are right without any time or danger penalties. What I'm saying is, it's nice to know how it works, and to know you can do it if you want. As far as the cruise control, if you're good, you can do better mileage wise than it can. You can anticipate hills, traffic, etc. It can't. But it doesn't get tired, and you will. I use cruise. I just set it a little slower than I used to drive. Still at the limit, as I don't want to cause traffic problems, but not way above as many drivers do. Replies to this message: jana6 (Jul 16, 2007 10:23 am) pathstar1 (Jul 16, 2007 5:56 pm)
#56 of 113 driving a Prius uphill (optimal GPH) by semenzato Jul 15, 2007 (8:29 pm)
We live on a hill at about 1000 feet and we have to climb most of those when we go home. I noticed that on the uphill stretch the fuel consumption seems to stay always around 14-15 MPG independently of the speed (usually between 30 and 40 mph). I have begun wondering what's the optimal GPH for this car (Gallons Per Hour), and how much its efficiency changes as a function of GPH. I am assuming (but I could be wrong) that RPM is a function of GPH. For instance, if I drive at 60 mph and the fuel consumption is 30 MPG (which means I am burning fuel at a rate of 2 gallons per hour), I expect that the engine RPM is the same as if I were driving at 40 mph and 20 MPG (still 2 gallons per hour). I see no reason why the computer should pick different RPMs for the same power demand, since the transmission allows for infinitely adjustable ratio. Does anybody have an opinion, or, even better, solid information on this? Thanks! Luigi
#57 of 113 Re: Prius always starts on gas engine [pathstar1] by jana6 Jul 16, 2007 (10:23 am)
Replying to: pathstar1 (Jul 13, 2007 11:53 am) Thanks so much. I know what you are talking about the gas peddle play (as I call it) and you are right, it does take some effort. If I'm not concentrating on it all the time, I goof! The cruise seems to do a much better job than I can on a continual basis. I'd been amazed at the gas mileage of those who "bragged" about getting over 100 etc. And using the glide method at highway speeds the way I know it just didn't seem to be the logical way to do it unless they were speeding up way over the speed limit and then coasting and dropping way below the speed limit. I just thought that would tick off the traffic around me! (And even doing that at highway speeds, I had a hard time believing the super high mileage they were claiming!) Either that or they were able to get that kind of gas mileage because they only drove in the 40-50 mph range. I can see how that could happen then. Well, again, thank you. I don't feel so "dumb" now. It was what I thought! Jana6 Replies to this message: pathstar1 (Jul 16, 2007 5:56 pm)
#58 of 113 Re: Prius always starts on gas engine [jana6] by pathstar1 Jul 16, 2007 (5:56 pm)
Replying to: jana6 (Jul 16, 2007 10:23 am) The hypermilers travel quite slowly. Average speeds of 25-35 MPH from what I've read. They pick level low traffic roads, and/or low traffic hours to do their thing. I've found the optimum speed for the Prius mileage wise in "normal" driving is between 70 and 80 km/hr. That's about 43-50 MPH. I can maintain about 3.7 l/100 km at that speed.
#59 of 113 Prius goes around 50 mph on the sloped freeway... by bluemoonseller Jul 17, 2007 (9:14 am)
Prius goes around 50 mph on the sloped freeway... Do i need to use gear "B" when uphill? What does the "B" gear do? Replies to this message: pathstar1 (Jul 17, 2007 12:42 pm)
#60 of 113 Re: Prius goes around 50 mph on the sloped freeway... [bluemoonseller] by pathstar1 Jul 17, 2007 (12:42 pm)
Replying to: bluemoonseller (Jul 17, 2007 9:14 am) "B" uses the engine for braking. It's for mountain descents. I don't understand what you mean by "Prius goes around 50 MPH on the sloped freeway". The Prius is quite capable of going much faster than that, even on steep freeway hills. I maintained 110 km/hr (68 MPH) with no problem, while other vehicles were slowing climbing the steepest part of hwy 5. I think that was an 8% grade. If you're at very high altitude, the car will slow.
#61 of 113 Re: Unexpectedly Low Prius Gas Mileage [pathstar1] by gardener3 Jul 20, 2007 (3:11 pm)
Replying to: pathstar1 (Jul 12, 2007 8:57 pm) My Prius (Touring #2)has about 800 miles and I'm still trying to figure out how to get better MPG. On a trip to Yakima I drove 310 miles (both ways) and used 7 gallons of gas, that makes about 44.3 MPG, the panel reading was showing only 42.4 MPG average at the end of the trip. It seems to me that the reading is not very accurate, almost 5% off. Did anybody make a similar test? I'll try again when I fill up. Replies to this message: carz89 (Jul 20, 2007 7:46 pm) gardener3 (Jul 21, 2007 10:11 am) pathstar1 (Jul 21, 2007 1:55 pm)
#62 of 113 Re: Unexpectedly Low Prius Gas Mileage [gardener3] by carz89 Jul 20, 2007 (7:46 pm)
Replying to: gardener3 (Jul 20, 2007 3:11 pm) The onboard computer and the "by hand" methods of determining MPG will yield different results for many reasons, but they should be reasonably close, if not for one tank then after many tanks. One reason is the volumetric endpoint at which you decide to stop filling the tank changes from tank to tank. Another reason is that the "by hand" method relies upon the accuracy of both your odometer and the gas pump flow meter, which are both accurate to better than 1%. The car's onboard computer relies upon the accuracy of the odometer and the fuel flowmeter. I haven't found a published accuracy for the fuel flowmeter, but it's probably the least accurate component of the calculation. I'm guessing it can be off by 5% or so. Toyota doesn't use a thousand-dollar flowmeter, so your Prius is stuck with the difficult task of measuring very small volumes of fuel over a period of time. Think about this: Let's assume, for simplicity, 50 mpg and an average speed of 25 mph. That yields a volumetric flow rate of 0.5 gallons/hour. If your engine is running only half the time, then it's 1 gallon/hour while running. Converting, that's approximately 2 ounces/minute, or 0.036 ounces/second. Using 30 ml/oz and 20 drops/ml, that comes out to 20 drops/second. The computer is constantly computing an instantaneous mpg, then integrating over time. So, small errors in the flow measurement (fractions of a drop) will result in a noticeable error in the calculated MPG readout. My Prius computer yields a typical 50 MPG over a full tank, yet my "by hand" method consistently yields about 2.5 MPG lower. I can live with that, especially knowing that my old 1996 RAV4 (2wd, manual shift) got about 22 MPG (downhill, with the wind from behind) Replies to this message: gardener3 (Jul 21, 2007 10:11 am) pathstar1 (Jul 21, 2007 1:55 pm)
#63 of 113 Re: Unexpectedly Low Prius Gas Mileage [carz89] by gardener3 Jul 21, 2007 (10:11 am)
Replying to: carz89 (Jul 20, 2007 7:46 pm) Thanks for coming back. I'll have to fill up a few more times to check computer and "by hand" readings. It would be good to know what kind of system Toyota uses for measuring use of gas. It is in software which perhaps gets updated/changed with new versions. I'll keep track of gas purchases and this way later get more readings with higher mileage. It is interesting to note that your computer reading is higher than your "by hand" method, while mine is the opposite In any case Prius is a great car! Replies to this message: pathstar1 (Jul 21, 2007 1:55 pm)