Can't break 40MPG...

[Sodium Duck]

I can get 39.XX, but not 40. I use DFCO constantly down hills, coast in neutral down smaller hills, use DFCO to come into red lights, putter away from stops very slowly, have my tires at about 45PSI (that was the biggest help, about 2MPG), drive 50-55MPH whenever I can, don't use the A/C or defroster settings, keep windows up/cracked a little instead of down, I stay fairly close to big rigs and other large vehicles when I'm on the highway, too.

Does anyone else have more idea's on what I can do?

[KCALB SIRAY]

Not sure what the problem is as I can see 40 to 42 without doing any of that on a daily basis. There are so many more things you can do and you are not doing that will help, but I'll let those who practice these chime in. Have you checked out any HM forums to see what you are missing or searched Bailouts threads?

[Loren]

Originally Posted by Sodium Duck

I can get 39.XX, but not 40. I use DFCO constantly down hills, coast in neutral down smaller hills, use DFCO to come into red lights, putter away from stops very slowly, have my tires at about 45PSI (that was the biggest help, about 2MPG), drive 50-55MPH whenever I can, don't use the A/C or defroster settings, keep windows up/cracked a little instead of down, I stay fairly close to big rigs and other large vehicles when I'm on the highway, too.

Does anyone else have more idea's on what I can do?

I assume you're talking about full-tank mileage? And you don't have a ScanGauge? It can be harder to do than you think. Much depends on the conditions you drive in. I know for me, there is one trip I make that I can almost never get more than 36 mpg on. It's fairly close to home, it's just the amount of traffic on that road, a good portion of it slightly up hill, and the way the lights are timed... it all works against me. Anywhere else, I can easily get 38-40, sometimes up to 44 is I'm lucky and/or trying hard.

One thing I notice you said is that you "coast in neutral down smaller hills". Is that a mis-statement? If not, that's part of your problem. Remember, when you go DFCO, you use NO fuel, when you shift to neutral, you're using fuel to idle. The benefit is normally to use DFCO on the smaller hills, just for a few seconds. What I like to do is hold the throttle at the crest of the hill and gain a few MPH before lifting, then DFCO to 5mph (or 10 if there's nobody behind me) below the speed limit. Save the neutral coast for LOOOOONG downhill stretches, that's where it's useful. (it's a technique that I never use, because there simply are no hills that long here)

I think Pulse & Glide is your answer. That allows you to use DFCO more. VERY gently accelerate (and I mean gently... like barely breathing on the throttle) up to 5 or 10 mph over the speed limit (but not over 60... MPG plummets accelerating over 60), then lift and DFCO coast back down to 5-10 mph under the speed limit. Lather, rinse, repeat. Blend this technique with the natural terrain so that you're not trying to accelerate up hills, and you're extending your coasts by coasting down hills. Just remember, "light on the pulsing, heavy on the gliding"!

Give it a shot.

[supmet]

Originally Posted by Loren

One thing I notice you said is that you "coast in neutral down smaller hills". Is that a mis-statement? If not, that's part of your problem. Remember, when you go DFCO, you use NO fuel, when you shift to neutral, you're using fuel to idle. The benefit is normally to use DFCO on the smaller hills, just for a few seconds. What I like to do is hold the throttle at the crest of the hill and gain a few MPH before lifting, then DFCO to 5mph (or 10 if there's nobody behind me) below the speed limit. Save the neutral coast for LOOOOONG downhill stretches, that's where it's useful. (it's a technique that I never use, because there simply are no hills that long here)

I think it really depends on the hill. Some small hills I can gain 5 mph if I go into neutral, or lose 5 mph if I use DFCO... Now is that 10-15 seconds of no fuel vs very little fuel gonna make up for having to accelerate 10 mph? Then again, on a perfect hill I can maintain speed with DFCO, and then I'd use DFCO for sure.

[b_hickman11]

Originally Posted by Sodium Duck

I can get 39.XX, but not 40. I use DFCO constantly down hills, coast in neutral down smaller hills, use DFCO to come into red lights, putter away from stops very slowly, have my tires at about 45PSI (that was the biggest help, about 2MPG), drive 50-55MPH whenever I can, don't use the A/C or defroster settings, keep windows up/cracked a little instead of down, I stay fairly close to big rigs and other large vehicles when I'm on the highway, too.

Does anyone else have more idea's on what I can do?

Move to Texas or somewhere else where there is really hot weather and your mpg should go up about 5 mpg.

[SpaceShot]

I would agree with Loren that you may do better by coasting in gear on short hills, and only putting it in Neutral on very long hills. From the end of my road to my house is just over a mile of slight decline and a couple of flat stretches. Using neutral there works to lower the trip average, elsewhere on the commute it doesn't help.

Look at your route and see if going a few blocks to a half mile out of your way brings you to a right on red instead of a full stop. If you can minimize stops or find a parallel route that lets you glide along at 45 Mph or so for a longer stretch, you should see the trip average improve.

I average 40 in my manual LB and I am trying to bump it up to 45. (which I can easily do in July) However, beyond tire pressure and driving style, I did do some minor mods.

1. After market cruise control - $225, 0 Mpg gain, but more comfort on 70 min commute
2. K&N replacement air filter - $40 AutoAnything.com, 0.5 Mpg
3. Partial upper grille block - $0 (used magnetic door signs cut to fit) 1.5 Mpg
4. Replace stock antenna with stubby - $12 CarAccessory.com, 0.25 Mpg ($0 if goto only MP3 and removed antenna)
5. Racing Disk smooth hubcaps - $80 HotRodGirl.com, 0.1 Mpg? but looks sharp...

6. ScanGuage II - $160, 1.5 Mpg (when remembering to keep Tach < 3050, TPS < 25)

Beyond tire pressure and driving style, temperature and route can be your next biggest factors. If you can change the route or drive time to avoid traffic and get to the point of cruising along at 45 Mph for 15 min or more, you should see trip average improve.

[Loren]

Public service announcement: "Right on Red" doesn't legally mean that you don't have to stop. Unless there's a yield sign there, or the light is green, you have to stop!

Alternate routes that allow you to maintain a more constant speed, and more importantly to reduce your time spent STOPPED and idling are good. When I was driving across the county (all urban driving, Pinellas County) every day, I found the fastest route... no less than 45 minutes (if I didn't get stuck on a bridge, or behind an accident on the highway), and the most efficient route... about 50-55 minutes. The faster route had me going 60+ mph and MPG suffered. The slower route cost me 5 minutes or so, but allowed me to get over 45 mpg by never going over 45 mph and maintaining a more constant speed.

[BailOut]

SodiumDuck,

Some good advice has been given so far and I would like to add to it by discussing your idling habits, which you made no mention of. The Yaris' 1.5L engine uses roughly .25 GPH at idle, and considering one may idle for up to 2 hours per tank this can impact your overall fuel economy by as much as 2 MPG.

Please consider turning off your engine if you will be stopped for more than 7 seconds. That is the break even time for the wear and tear and fuel usage of a warm start.

[supmet]

Originally Posted by BailOut

Please consider turning off your engine if you will be stopped for more than 7 seconds. That is the break even time for the wear and tear and fuel usage of a warm start.

7 seconds is the break even point for gas consumption. What is the break even for wear on the starter and other components, or a "total cost" break even point. I've had toyota starters go bad before 100k miles with 5-6 starts a day max. Also, until you reach peak operating temperatures, turning your engine off and letting it cool down, and forcing it to reheat will increase engine wear, and reduce mileage.

I'd say its closer to 12-13 seconds to break even, and then you should only do it if you KNOW your gonna be 20 seconds or more(when you just roll up to a light changing) A few 2-3 second stops that you thought were gonna be longer will negate everything your doing, and all you're left with is a burnt out starter.

[BailOut]

Originally Posted by supmet

7 seconds is the break even point for gas consumption. What is the break even for wear on the starter and other components, or a "total cost" break even point. I've had toyota starters go bad before 100k miles with 5-6 starts a day max. Also, until you reach peak operating temperatures, turning your engine off and letting it cool down, and forcing it to reheat will increase engine wear, and reduce mileage.

I'd say its closer to 12-13 seconds to break even, and then you should only do it if you KNOW your gonna be 20 seconds or more(when you just roll up to a light changing) A few 2-3 second stops that you thought were gonna be longer will negate everything your doing, and all you're left with is a burnt out starter.

Sumpet, please forgive me if I sound short here but I tire of explaining this over and over again. To your credit many of the rehashes of this subject were lost in the hack.

I say again, the break even time for the wear and tear and fuel usage of a warm start, not just the fuel usage, is 7 seconds.

We have all seen starters go bad before their time, just like any other electromechanical device, but how many times you start your car is not linear to how quickly the starter wears. For example I use my starter an average of 12 times each day and I just hit 42k miles. There are many other variables that come into play. If my starter were weak this would have already killed it off.

An extra 2 MPG is worth roughly $0.9/gallon with gasoline at $2.25. If a replacement starter costs $120 (the average price of every aftermarket starter for our cars offered by the O'Reilly/Kragen group) the break-even point is just 1,333 gallons fueled, or 2-2.5 years for the average American driver. What's more is that the aftermarket starters usually come with a lifetime warranty.

I'm at 2 years and 2 months of ownership on the OEM starter.

Owners with the manual transmission get even more benefit from turning off the engine as they can do it at any time, not just when stopped. This opens up the world of FASing to them (please see the stickied FE thread in this forum for more on that).

[supmet]

lol.. ok dude. Go ahead and turn your car off for 7 seconds, and save the 1/10th of a penny in gas. I'm sure doing this 120,000 times you will never have to buy a new starter.

[BailOut]

Originally Posted by supmet

lol.. ok dude. Go ahead and turn your car off for 7 seconds, and save the 1/10th of a penny in gas. I'm sure doing this 120,000 times you will never have to buy a new starter.

No one ever said I wouldn't need a new starter at some point (we all will), only that the fuel savings more than pays for it and that its replacement will come with a lifetime warranty (meaning you'd only have to replace it once).

[supmet]

Originally Posted by BailOut

No one ever said I wouldn't need a new starter at some point (we all will), only that the fuel savings more than pays for it and that its replacement will come with a lifetime warranty (meaning you'd only have to replace it once).

saving less than $0.01 each time will never pay for a new starter, or fix any of the other problems you are creating with unnecessary starts and stops.

15 seconds, we can start talking. 7 seconds is pure nonsense.

[BailOut]

Originally Posted by supmet

saving less than $0.01 each time will never pay for a new starter, or fix any of the other problems you are creating with unnecessary starts and stops.

15 seconds, we can start talking. 7 seconds is pure nonsense.

I've already done the math and shown it to you. That you choose not to believe it is your prerogative, but it doesn't change the facts. 7 seconds has been tested, tried and found be true time and again.

[supmet]

Originally Posted by BailOut

I've already done the math and shown it to you. That you choose not to believe it is your prerogative, but it doesn't change the facts. 7 seconds has been tested, tried and found be true time and again.

LOL.. I'm done after this.

Your math is what most people would describe as fuzzy. Very few people idle 2 hours per tank. If they do it is in stop and go traffic where they wouldn't even get 7 seconds to stop. Yet you use that as your baseline of breaking even.. 1,333 gallons my ass.

Here's some math

0.25 gallons/1 hr = 32 oz/3600 s = 0.06 oz/ 7 s

2.25 dollars/ 1 gallon = 2.25 dollars / 128 oz = 0.001 dollars / 0.06 oz

1/10th of a penny saved every 7 seconds of idling.

You are the one that chooses to ignore the simple math.

[1stToyota]

Originally Posted by BailOut

I've already done the math and shown it to you. That you choose not to believe it is your prerogative, but it doesn't change the facts. 7 seconds has been tested, tried and found be true time and again.

I saw math on a DIY project, but not everybody will be able to or want to buy a starter and put it on themselves...might have to refigure your math to include towing, retail pricing and labor.

Oh, and O'Reilly Auto Parts is my favorite place to order parts from, but my average was a little different than the $120.00 that you listed.

w/ Cold Climate Package: $107.97
w/o Cold Climate Package: $264.59

...and those are the cheap prices, not the national suggested retail prices.

[Sodium Duck]

Right, anyways...

When I coast in neutral down hills, my reasoning was that I would be able to maintain speed and coast for longer without hitting the gas. If I use DFCO in those instances, I would have to hit the gas again far sooner, and probably use more gas in the end. Did that make sense? I hope so lol.

I don't know, when I'm going down a hill I usually decide if I could coast longer than I could DFCO. Sometimes I'll end up coasting in neutral for a bit, the using DFCO at the end to come back under the speed limit. It's a confusing mix. But maybe I'll try JUST using DFCO and see if it makes a difference.

Also, sometimes I try pulse and glide but I never follow through with. It's tough to do while maintaining a reasonable flow in traffic. I think I'll try and incorporate when possible from now on and see how that goes, too.

[BailOut]

Originally Posted by Sodium Duck

Also, sometimes I try pulse and glide but I never follow through with. It's tough to do while maintaining a reasonable flow in traffic. I think I'll try and incorporate when possible from now on and see how that goes, too.

Have you looked into the Hang Time technique which is stickied at the top of this forum? It is much less labor intensive than P&G, and it lets you maintain a narrower speed band.