Hypermiling techniques WASTE lots of fuel?!?

[imzjustplayin]

Originally Posted by bobski

You know that may be the manufacturer's spec in some cases, right? The spec for my mom's Outback is 28 psi IIRC... It wouldn't surprise me if some older luxo-barges are set even lower.
Higher pressure reduces rolling resistance and all, but it also affects ride quality (the tires act as springs to some degree - higher psi = higher spring rate), ultimate traction and handling to some degree. When I tried pumping up my mom's outback to 40 psi, it picked up a pretty noticeable vibration at around 70 mph, as if a wheel were out of balance.
I'm just pointing out that while keeping people's tires filled is nice, cranking up the pressure past spec can have adverse effects.

maybe it was out of balance and you just didn't notice when you had your tires at the "stock" psi since they were so squishy.

[GasSavers_bobski]

Originally Posted by *************

maybe it was out of balance and you just didn't notice when you had your tires at the "stock" psi since they were so squishy.

It's possible. Another possibility being that the additional pressure caused the tire to expand more in one area than the others (due to poor manufacturing or whatever), throwing the wheel out of balance. Either way, reducing the pressure fixed it. We actually later discovered that one of the rear shocks had gone bad, which may have made the imbalance more pronounced.
As a side note, the vehicle's handling characteristics (would do a diagonal oscillation when going over bumps) in the time between picking it up from the dealer and replacing the shock suggest that the shock was bad either from the factory or from an abusive test-drive. I'm not sure what to think about that since Subarus are supposed to be decent quality cars.

[imzjustplayin]

Originally Posted by bobski

It's possible. Another possibility being that the additional pressure caused the tire to expand more in one area than the others (due to poor manufacturing or whatever), throwing the wheel out of balance. Either way, reducing the pressure fixed it. We actually later discovered that one of the rear shocks had gone bad, which may have made the imbalance more pronounced.
As a side note, the vehicle's handling characteristics (would do a diagonal oscillation when going over bumps) in the time between picking it up from the dealer and replacing the shock suggest that the shock was bad either from the factory or from an abusive test-drive. I'm not sure what to think about that since Subarus are supposed to be decent quality cars.

I drive fairly new cars and every car I've increased the pressure on has caused no adverse effects like you've described, usually just ones that are mostly expected like more oversteer, rougher or possibly quieter ride etc, not like bouncing excessively or pulling hard or something like that.

[OldCorolla]

When I return to the states and start driving for the best FE I can possibly get , I wont really care what the people around/behind me are doing with their time. I will have a sticker that says I'm driving for MPG, or something along those lines.

[soda_pop503]

Originally Posted by theclencher

Take a macro view of it: during the course of a hypermiler's trip, how many other vehicles barrelling along come up on a hypermiler doing extreme P&G or something and due to conditions or them not realizing what is going on, hit the brakes, de-activate the cruise control, slow way down (or not) and accelerate to pass again. Here we have one vehicle- the one that probably would be getting the best FE out of the lot of them at steady state cruise- potentially causing dozens or hundreds of guzzlers to interrupt their gait and guzzle even more... potentially causing more fuel useage than if the "hypermiler" went with the flow of traf f***! Of course if the hypermiler has the road to himself he is saving fuel compared to steady state cruise, or beating on it.

Yeah. I've thought of that too. I'm not going to lie though. 95% of my hypermiling motivation is for my own wallet. So I just laugh at those guys. But think of it the other way as well.

They use bad driving habits all day long and you are only adding a tenth of a percent to it. Eventually they'll get used to the "strange" habits of hypermilers.

as far as i'm concerned, until then they can waste all the money they want.

[Jay2TheRescue]

What bothers me the most, is when I'm in my 4wd pickup truck in the right lane of the highway, with the cruise set on 60. Invariably a Prius comes barreling up at 80+ MPH, weaving in & out of traffic, and cutting people off. In all likelihood I am getting better mileage than that Prius.

[GasSavers_bobski]

Originally Posted by Jay2TheRescue

In all likelihood I am getting better mileage than that Prius.

I'm skeptical. Even under WOT, high RPM acceleration, my CRX (using 15 year old engine tech) gets 8-10 MPG. While that Prius may be weaving through traffic, that doesn't necessarily mean they're accelerating hard. They may be effectively cruising at a speed 15 MPH faster than traffic, weaving as needed to avoid braking.

[Jay2TheRescue]

I wonder if someone with a Prius and a Scangauge can chime in with the instant MPG reading of a Prius cruising @ 80 MPH.

[FrugalFloyd]

A Prius can cruise all day at 60 mph, getting 60 mpg, on level ground. Push one uphill, and mpgs drop to 15-19. Push one at 80 mph, and mgg probably drops to or below 40 - still way better than any FSP under the best conditions.

[slurp812]

Originally Posted by zpiloto

Ah but the hypermiler is causing the cellphone talker to pluse and glide even if they don't want to. The question would be does the 30% or better FE of the hypermiler make up for the 10%-15% decrease of FE of the stomp and go driver.

If hypermiler drives a civic, and the stomper drives a explorer, it may be a wash.