Mileage difference with different drivers

<div class='quotetop'>QUOTE(scpilot @ Oct 16 2007, 07:04 PM) [snapback]526639[/snapback]</div>

Yes, same here. With the Prius 2007 when I drive same route, I get between 54-58 (some time on phone mpg drop). When my wife drive she get 48-50 mpg. Also when I drive 2007 Sienna; I get 26-28 mpg 100% Freeway . When she drive; she get 20-22 mpg 100% Freeway.

 

pretty easy one actually. lead foot or jumb rabbit starts. Driving style makes all the difference, if you drive this car like other cars the mpg goes down big time.

 

Hi Scpilot,

Yep, I agree with MJGreen. You are more lead footed than your wife, and that is why you are getting better mileage.

The source of the recommendation to not do quick acceleration with a standard car is the need to give the standard engine an extra squirt of gas to get the engine to ramp up the RPM quicker. This is called "enrichment". This is responsible for that black puff of smoke out the back of that beemer up ahead. Poorly burned gas, is poor fuel economy, however.

The Prius does not have enrichment, it has a battery and a 60 hp electrical motor. So, the engine ramps up gradually in RPM, as the electric drive gives the torque at low speeds. Of course, flooring a Prius will not give good mileage either. But there is a fuel economy sweet spot for accelleration between 1/3 and 1/2 pedal depression up to the speed limit, then pull your foot all the way off the gas, and bring it back up to cruise power. Which is usually a little quicker than other cars in the morning, and about as quick as 80 % of cars in the evening. At least around here.

So, at the optimum quickness, the extra gas used to get to speed quicker, is offset by the extra time cruising with the engine off, and the higher efficiency of the engine at higher loads, both accellerating, and while cruising charging the battery for part of the cruise.

If you gradually accellerate, even if you keep it in electric, the mileage will be worse. Because the electricity needs to be replaced and unless you have a big hill to coast down, that costs gas. The Prius engine to wheels efficiency is better than than the engine to generator to battery to motor to wheels efficiency. Trying to stay in electric forces most of the energy to go through the latter (series hybrid) path.

 

I've driven a lot of automobiles in the last 30+ years. The Prius is by far the most sensitive (in terms of mileage) to driving technique of any automobile that I've ever driven. It is also the most fuel efficient automobile that I've ever driven.

Keith

 

I typically get 10% better mileage than my wife in any vechile we drive. I noticed she drives with a 'choppy' right foot. In other words, she is constantly tapping the gas pedal and not being gentle with it. I always tell her to drive as if there is an egg under your right pedal. I don't think she understands.

 

<div class='quotetop'>QUOTE(MJGreen @ Oct 16 2007, 10:05 PM) [snapback]526660[/snapback]</div>

While I agree that binary pedal operations are bad for FE, I wouldn't say driving a Prius like any other car causes poor FE. If a driver gets poor FE because of their style, it will be show up regardless of the vehicle.

BTW - I have heard of Prius drivers driving "angry" and getting better than thier normal FE. When I say "angry," I mean preoccupied while driving, aggressive, or not caring about anything but getting to their destination (mad at a spouse, late for a meeting, etc).