Fuel Efficiency and the Yaris

[Pars]

Bailout, Thanks for the tip regarding the engine cut-out, it's saving me $200/year. I use to think coasting in neutral was the proper way to save gas, but once I learned that the engine cuts fuel-flow when coasting, I'm now always in gear while coasting.

[Pars]

Yep, the 401 is a treacherous place to be, if you're in the GTA area. It's not so bad during rush hour, when everyone is force to slow down, but during the day, when you've got congested areas with the occasional opening for the idiots, it makes for a bad formula. That's why through-out the day, more times then not, some of the lanes are blocked-up from a accident. Plus there's all the constructions, that adds to the danger, since it forces the speeders to share the lanes with the regular drivers and takes up critical shoulder space. (BTW, shoulders are very good to have...which explains all the tragedy on the 400 near hwy 89...there's no left shoulder in that particular stretch...stupid.).

Normally, I'm a advocate for speeding. I'll be one of those guys cruising in the middle lane waiting for the speeder to pass by, so they can clear the way for me and also give me a better chance to avoid the traps. But, specifically the 401 in the GTA area, the speed limits should be followed religiously (unless you need to take it up a bit to steer clear of a truck). Then there's area like 401 near Napanee, a beautiful stretch of highway, which can safely support speeds of excess of 160km/hr. But, for some unknown reason (probably something personal), this dinky no-name town in the middle of nowhere has taken it upon themselves to aggressively police this particular stretch of highway and is crashing-in big time. It makes sense to have higher speed limits for these particular stretch of highway, not only does it eliminate danger caused by these 2-bit towns who put unsafe speed traps, but it also acts as a warning to drivers to slow down when approaching a questionable area, since the higher speed limits will suddenly go back to normal. It's already being done for the rural highway but not the major highways.

Anyways, I digress, but I know Bailout is an advocate for the 88km/hr speed limit, but he probably mostly travel the country highway (which are not setup to manage high speeds) and his time is probably paid for, even if he's late (assuming he needs to work).

[hystria]

Not sure if this was discussed here in this topic...

Running with "a emptier gas tank", saves quite some weight, half a tank means 40pounds less. the car handles a little bit better and I've noticed a zipper acceleration when the tank almost get empty - only my impression ?

[Canuck]

Regarding faceout parking, wouldn't backing INTO the space to be face-out use as much gas as backing OUT of the space?

And keep in mind that in jurisdictions with only one plate, it is usually illegal to park face-out.

[Yaris Newbie]

So, here's a question from another post that got some response there but might be more suitable here. I was referred here anyway.

Regarding Driving under load.
In rolling hills, where coasting downhill is possible, but it is obvious that I will need to climb the next hill with at least some pressure on the accelerator... should I just forgo coasting down the hill and maintain constant pressure on the gas pedal the entire time (down and up the hill)?

Given these points already made:
Driving slower (to a point) increases gas mileage.
Moderate drafting (please no safety debate) increases gas mileage.

Would it be better to go 50-60 alone or to increase speed to 70 or slightly more to gain a draft off of a transfer truck (18 wheeler)?

At what speed should (the rare times I use AC) I roll up the windows and turn on the AC?

Will a cold air intake improve MPG?

Is there a difference in running the AC at a lower fan speed compared to higher temperature (more red on the circular dial) compared to turning the AC on for a while then off for a while? Or is the compressor doing the same amount of work in all three situations?

[flagmunkey]

Originally Posted by Canuck

Regarding faceout parking, wouldn't backing INTO the space to be face-out use as much gas as backing OUT of the space?

And keep in mind that in jurisdictions with only one plate, it is usually illegal to park face-out.

i think what is ment is that you go into a dual spot and stop in the opposite one that is intended to be parked in, moving or coasting forward the entire time.

[BailOut]

Originally Posted by Yaris Newbie

should I just forgo coasting down the hill and maintain constant pressure on the gas pedal the entire time (down and up the hill)?

On smaller hills, yes. On larger hills, no.

Originally Posted by Yaris Newbie

Would it be better to go 50-60 alone or to increase speed to 70 or slightly more to gain a draft off of a transfer truck (18 wheeler)?

While drafting does indeed offer decreased air resistance, it does nothing for rolling resistance. Going 50-60 alone is much better than drafting at 70. I only draft when I can find a proper vehicle going between 45 and 60 MPH.

Originally Posted by Yaris Newbie

At what speed should (the rare times I use AC) I roll up the windows and turn on the AC?

None. Windows down is always much more efficient than using the a/c. Mythbusters proved as much as well.

Originally Posted by Yaris Newbie

Will a cold air intake improve MPG?

Only if you drive like a testosterone-infested aggressive punk.

Originally Posted by Yaris Newbie

Is there a difference in running the AC at a lower fan speed compared to higher temperature (more red on the circular dial) compared to turning the AC on for a while then off for a while? Or is the compressor doing the same amount of work in all three situations?

The compressor is basically a binary unit, being either on or off. As such it doesn't matter what the fan is set on. If the a/c is on the compressor is clutched 100%.

[petesimac]

Bailout, I heard recently by the so-called experts, that one should roll their windows up when the speed of the car reaches 30 mph, as the drag reduces fuel efficiency -- have you heard this as well?

[BailOut]

I heard that, too, and a few of us on CleanMPG quickly debunked it. Using an SGII one can drive around at various speeds and watch for an MPG change with the windows up or down. You wont' find one.

Then do the same thing with the a/c on or off and watch your average MPG instantly drop by 10-15%.

We know that the windows down affects drag, but it does so at a fraction of an MPG. Between all my measuring efforts the only time I have ever noticed the drag is when I'm FAS'ing one section of my commute home. In that section I already have a lot of rolling resistance and not much of a grade to maintain my speed before the next climb, and if I have my window fully down with a strong wind catching in it I can lose an additional 2 MPH from 60 by the bottom of that 1/2 mile hill. That's not exactly earth-shattering.

This correlates with what the Mythbusters show found both in their initial testing and their re-vistiing of the myth.

[sherryberry]

I thought I saw a mythbusters episode that tried to see if you get better mileage with a/c or window down. Believe that the one w/ a/c ran out of fuel faster than the one with window down but I could be wrong since it's been a while since I've seen it.

[eTiMaGo]

hehe mythbusters rocks

[sherryberry]

Originally Posted by eTiMaGo

hehe mythbusters rocks

i watch it all the time. Or at least I try to watch it as much as I can i like explosions

[Pars]

For those who have the scangage. Is it possible to tell how much gas the car is using up while idling with the AC running?

Since it's hot outside and I don't want to disturb the little one's sleep, I might have the car idling for over 1/2 hr on occassions, just to make sure the little princess sleep isn't disturbed. The price for disturbing a babe's sleep is too high, so I'm not worried about the fuel cost, but it'd be nice to know.

[BailOut]

Pars,

Please remember that the cost of burning fuel goes far beyond the price you pay at the pump. If you would like her to have a future free of the Arab stranglehold on oil - and the wars that come with it - we must cut back on our fuel usage harshly, and if you would like her and her own progeny to inherit a planet worth having the lessening of our usage and consumption of all resources is totally necessary.

With that said, you can use the SGII's GPH (gallons per hour) monitor to see the fuel usage at idle.

[Canuck]

Originally Posted by sherryberry

I thought I saw a mythbusters episode that tried to see if you get better mileage with a/c or window down. Believe that the one w/ a/c ran out of fuel faster than the one with window down but I could be wrong since it's been a while since I've seen it.

But all it really proved was that for those vehicules (they were SUVs) ith those conditions, the windows down were more efficient than AC. I would not extrapolate to all cars. And there is a comfort thing too. windows down at 100kmh is really no fun.

[lgcharlot]

I can't wait to get my Yaris in a couple weeks and get on this fuel mileage bandwagon.

On a couple of long trips from California to BC (2000 miles round trip), I was able to average 37 mpg in my 5-speed Yaris hatchback, that's at an average speed of 70 mph (113 km/h). On a 450 mile trip last spring, I deliberately kept my speed in the 50~55 mph (80~90 km/h) range to see what kind of fuel economy the car was capable of if driven conservatively: got 45.2 mpg (astounding for a a non-hybrid car running California's E-10 gasohol blend). On "pure" gasoline (with no added ethanol, if that's even available anymore), the car might have been able to top 50 mpg.

When I was shopping for a small car last year, I considered the Prius and the Insight, and quickly came to the conclusion that, at $25,000 (with taxes and DMV fees), those hybrids are WAY too expensive and can't even come close to matching the cost-per-mile of ownership of the Yaris at $12,000 (or even the Corolla at $15,000). On the freeway, which is 90% of my driving, the Prius only gets 13% better fuel economy than my Yaris, and there's no way you would ever recover the $12,000 price difference within the typical lifespan of these cars (150,000 miles at best). Maybe I would by a hybrid if gas was $10/gallon, and getting the absolute maximum fuel economy was crucial. Too bad you can't get the European version Yaris with the diesel engine here in the US - they probably get 60 mpg.

[fenwayfanatic94]

surprised how much i know, surprises me how much more i could do. good information.

[NimbleYarisOwner]

Brian,

Can you give me more details on the solar trickle charger???

thanks allot!