Hi,
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Originally Posted by jrb_nw
I find that all this attention to gaining a few mpg often comes at the expense of one's attention to the road and other vehicles, . . .
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Predictive braking depends upon being aware of all traffic. I find I'm more aware, not less of the surrounding traffic.
Quote:
Originally Posted by jrb_nw
. . . and by nature of the speed variations, can sometimes even pose a hazard, as you mentioned. Just think what will happen when a million more Prius drivers are "pulse and gliding" to work in the morning.
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This is one reason why I advocate steady, slow speeds. I'll take a glide when conditions permit but my testing suggests P&G really needs significant speed changes to be effective. In a Prius, smaller speed changes can eat up the fuel savings with more engine start/stop loads. Starting and stopping a Prius engine takes fuel energy.
Quote:
Originally Posted by jrb_nw
. . . I also think if you are going so slowly as to cause other drivers to flip you off or get upset, it is ultimately a strategy that will backfire by further polarizing the "Greens" vs. the SUV drivers. I hate when I see a Prius holding up traffic like an old VW bus.
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This is handled by route planning so you can drive in slower traffic. For example, driving on an access road instead of the divided highway or taking an urban street short-cut instead of a highway. But 100 years of pre-hybrid car designs and subsequent traffic planning has led to what we call "normal" driving practices.
Quote:
Originally Posted by jrb_nw
. . . Why not just drive the car as you normally would drive a car,
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Non-hybrid cars have terrible, low-speed efficiency. Such cars are more efficient at highway speeds without stops. So drivers are conditioned to drive faster even over a longer route to minimize fuel costs. But introduce the hybrid drive and suddenly it is cheaper to drive the direct path at a slower speed than a longer path at highway speeds.
Physics tells us that with regenerative braking, a vehicle should be more efficient at slow speeds. Hybrids give us a chance to get back to driving the shortest path instead of a longer, high speed route. But it takes a hybrid drive system to make this mind-set change.
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Originally Posted by jrb_nw
. . . perhaps making a few subtle changes? I keep my the freeway speed between 65-70mph, back off slightly on grades, and minimize the A/C use when possible. Sometimes I use electric mode the last few miles home at 38mph on a lightly travelled boulevard. All of this allows me to achieve 45 mpg overall without any stress or anger from other drivers.
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You are learning the non-normal way of driving that hybrids make possible. For a gas-only driver, this is incomprehensible because the current gas-only cars work so poorly at low speeds.
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Originally Posted by jrb_nw
. . . I was holding 46.7 mpg, but I recently reduced my tire presssure from 40 to 37 psi to improve the ride and improve crosswind stability, and it dropped the mileage a bit. It is still great mileage, and I enjoy the car a lot more this way.
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An active suspension can achieve this same effect with high pressure tires. Today, the 'soft' part comes from air compression and heat loss in the tires. An improved shock and suspension system can 'dial-in' the ride and handling desired without the tire heat loss.
Bob Wilson