Totally puzzled about how others are doing it.

[ketel0ne]

I have started to cut my commute into pieces. The first piece is rural hilly roads for 10 miles from my house. At the end of that segment I am usually sitting at about 33mpg. Here is why this is so puzzling. I can coast, drive as slow as I want etc. I see on here entire commutes that are 10 miles and less where people are getting 50mpg+ via SG. The first 2 miles of mine I can only get to about 22mpg. I know everyone's car, drive is different, but I just think I am missing something simple. It takes almost a mile for me to compensate for getting out of my driveway and getting to the first downgrade for coasting.

I know I am asking for critcism, but in reality advice doesn't have to be negative.

[MetroMPG]

I see on here entire commutes that are 10 miles and less where people are getting 50mpg+

With automatics?

I wonder if auto transmissions have a significantly higher penalty during warmup. It's essentially a fluid drive until the torque converter locks up, and the fluids are far more viscous and energy-wasting when they're "cold".

[Silveredwings]

I'm pretty sure an engine preheater would make a huge difference for me. When I start a trip with a cold engine, I gradually increase the car's mpg as the engine oil heats. Note: the coolant heats fairly quickly (inside of a mile), but I watch the oil temp (a separate instrument) rise much more slowly. The car doesn't peak until the oil is hot.

I think I recall a thread on engine preheaters (or maybe that was on MetroMPG's site)

[ketel0ne]

I am going to try the same segment tonight when the car is hot to a-b the difference. Our ambient temp outside is going to be constant all day. So the car will be the variable.

[MetroMPG]

We've talked about it here too (do a search), but the link on my site is: http://www.metrompg.com/posts/block-heater.htm

It would benefit any car, at any time of year (obviously more the colder the soak).

This year I became a year-round block heater user. I'll plug the car in for half an hour to 45 mins before a "cold" start even in warm ambient temps.

[MetroMPG]

That's a good idea, ketelone.

[argylesocks]

It takes almost a mile for me to compensate for getting out of my driveway and getting to the first downgrade for coasting.



i have hurd lots of negative comments on coasting in neutral with an auto.

i will leave the pro's to comment on this... but maybe something that should be addressed, sooner than later.

[Sludgy]

With automatics?

I wonder if auto transmissions have a significantly higher penalty during warmup. It's essentially a fluid drive until the torque converter locks up, and the fluids are far more viscous and energy-wasting when they're "cold".

Unbelievably, my F350 diesel has a valve in the exhaust line that partially closes when the engine is cold! This makes the engine work harder and warm up faster. My cold weather FE sucks because of this.

[coldtotouch]

i have hurd lots of negative comments on coasting in neutral with an auto.

i will leave the pro's to comment on this... but maybe something that should be addressed, sooner than later.

a mechanic once told me it puts excess strain on the transmission shifting it from drive to neutral constantly.

I really don't know how far its true.

[ketel0ne]

a mechanic once told me it puts excess strain on the transmission shifting it from drive to neutral constantly.

I really don't know how far its true.

From what I have read on the internet it is only second to the synthetic vs. normal oil debate in volume of pages and opinions that vary.

[argylesocks]

From what I have read on the internet it is only second to the synthetic vs. normal oil debate in volume of pages and opinions that vary.

i was thinking more about how its not keeping the gears lubricated.
the same reason why you cant tow an auto on the drive wheels....u'll loose your tranny by the time you get there! saturns had a disengauge feature, and then became the 'towing vehicle of choice'... for those wiht trailers that tow thier cars behind.

[SVOboy]

Unbelievably, my F350 diesel has a valve in the exhaust line that partially closes when the engine is cold! This makes the engine work harder and warm up faster. My cold weather FE sucks because of this.
Man, I believe you. Some BMWs have it too!!!

Anyway, I think it's mainly because of the auto, which is certainly an obstacle to overcome. Me, I'd still be gettin ~40 mpg if I were driving auto. Hopefully zpiloto will speak up with some of his killer auto charm.

[rh77]

IIRC, coasting in N for a short period of time, engine on or off, will not produce enough friction to damage the gearsets or TC. Towing the vehicle for hundreds of miles is another story.

For those with problems getting into closed loop and TC lockup, the fastest and easiest solution is an OEM Engine Block Heater (EBH). It works wonders for me in the Winter, even when parked in the garage. You'll notice a difference almost immediately, and you'll appreciate the instant toastiness of the cabin heater as well :thumbup:

RH77

[zpiloto]

Your pretty limited with an auto. Your commute owns you if it's not friendly there is not much you can do about it. It might not be the coasting it might be the acceleration. Note your shift points and the FE at each one so you can use the best speed for the condtions. My madza get better mileage with rapid acceleration to the final shift, which happens around 45mph and the Honda van with slow acceleration. Set up a mile course accelerate slow to 55 and fast to 55 and see which one gives you the best milage at the mile point. If you can take different routes you can use start exploring. Until I got the SG what I thought was the best route was actually the worst.:o . For me I found route that allowed me to keep the speed aound 45 which after the final shift gives good FE. On the hilly part drive with the SG on Load and while your climbing let it bleed off as much as the folks behind will let you. Most of all it's a on going process and takes time to get good at it. Don't be afraid to experiment with stuff what works on some cars dosen't on others. Testing and experiments kills the FE but it pays off in the long run. Good luck and keep after it.:)

[rh77]

Your pretty limited with an auto...On the hilly part drive with the SG on Load and while your climbing let it bleed off as much as the folks behind will let you. Most of all it's a on going process and takes time to get good at it. Don't be afraid to experiment with stuff what works on some cars dosen't on others. Testing and experiments kills the FE but it pays off in the long run. Good luck and keep after it.:)

I completely agree. You have to have some sort of instant feedback like a ScanGuage to actually see the results of your experimentation, or to collect trends over a tank. I've really been getting into the constant pedal pressure technique on hills -- building-up momentum going down, keeping the TPS steady, and ascend the hill with the same FE (albeit slowing down a bit). Every car is different even with identical models, years, and features, so general rules can guide you to what works for your vehicle.

RH77

[ketel0ne]

Well the same test tonight, yielded 41mpg + with the car fresh off the commute home. So it has to be "cold" the oil, trans etc. is really not effecient at all.

[zpiloto]

Well the same test tonight, yielded 41mpg + with the car fresh off the commute home. So it has to be "cold" the oil, trans etc. is really not effecient at all.
41 hot whats the FE on the trip in that direction when it's cold? My cold start commute can vary 2-3 MPG depending on traffics and lights etc.

[JanGeo]

If you are coasting in neutral in an automatic keep the engine running - the seals are lubricated by the oil and can burn out really fast if the engine is not keeping everything presurized and lubricated. Shifting back into gear in an auto make sure you are going slow and give it some gas to match the rpm for the speed. Remember you can alway just keep it in gear and give it a little less gas yet keep it moving forward - a little gas saved will not pay for a transmission overhaul.

Yup a warmer car runs a lot better than a cold car - my first mile is killer when cold - go real easy on the gas pedal - most of the fuel is going into heating the engine and transmission.

Block heater BE REALLY CAREFUL if you put ANYTHING into the cooling system. Toyota coolant is really sensative to metal contamination and can cause corrosion if messed with like adding regular water instead of distilled.

[ketel0ne]

41 hot whats the FE on the trip in that direction when it's cold? My cold start commute can vary 2-3 MPG depending on traffics and lights etc.

33mpg

[AlexK]

hi ketelone,
Our cars are the same except for the transmission (i'm sure I am the one you are referring to who got >50mpg in an 8 mile trip). What I did to do that is accelerate at maybe 15% throttle to 2000 rpm in each gear before shifting. I would get up to speed (35 in a neighborhood or 60 on the highway) and then coast for a while in N, repeat. That was with a "cold" (40C) engine at the start. I think the auto trans may be the biggest influence.
I checked my scanguage calibration today and it is right on out of the box. I put in 9.88 gallons and SG said I used 9.9 gallons.

My friend likes my car and is thinking about buying one just like it but with auto transmission. If he does buy one we can do a similar trip and compare fuel usage.

Toyota makes a block heater just for our engine, it's part 00213-00885. I've found it for about $50 online. I just don't want to leave it plugged in all the time. What I save in fuel I would be spending in electricity (probably more). I wonder if they are thermostatically controlled.

[MetroMPG]

You won't spend more in electricity than you'll save. It's been discussed before (search the archives), but I think we figured it would cost a couple of cents to plug the car in for an hour. At my rates and with my BH wattage (300), it's about 3 cents for the hour.

The timer is a must if you're not around to un/plug manually. More than 2 hrs is wasted energy in normal (cold ambient) circumstances.

[Ted Hart]

I have started to cut my commute into pieces. The first piece is rural hilly roads for 10 miles from my house. At the end of that segment I am usually sitting at about 33mpg. Here is why this is so puzzling. I can coast, drive as slow as I want etc. I see on here entire commutes that are 10 miles and less where people are getting 50mpg+ via SG. The first 2 miles of mine I can only get to about 22mpg. I know everyone's car, drive is different, but I just think I am missing something simple. It takes almost a mile for me to compensate for getting out of my driveway and getting to the first downgrade for coasting.

I know I am asking for critcism, but in reality advice doesn't have to be negative.

Hi, KetelOne!
Don't feel too bad about dealing with Mother Nature ... and coming up with the short end of the stick!
Look at what you are trying to do...start off from zero MPH and accelerating to "X" MPH, albeit slowly & gently! One, your auto. tranny is gonna slip&slide, trying to move that mass (how many hundreds of pounds?) from zero speed to cruising speed...wasting a lot of gas! Two, and we're talking average MPG here, right? ... at the end of your "trip" (however long) your average MPG is going to (mathematically) include all that "tail" you've been dragging- low speed, high gas consumption. This "tail" of bad numbers will be buried within your last (high speed, low gas consumption) number! Calculate the last, single number (MPG, average) and never ever forget the "tail" in the math! The further you go, the smaller the "tail's" effect on the single number! OK?
And, automatic transmissions are (generally) the curse of the effenciency-seeking driver! :D

[AlexK]

My friend bought an automatic transmission Yaris yesterday. One of these days we will get the scangauge in it and do some serious testing.

[AlexK]

We tried the Scangauge in my friend's auto Yaris. We managed to get over 47 mpg on the 15 mile return trip from Sears, 1/2 freeway, 1/2 city. This was with my coaching and coasting in "N" when possible. On the way to Sears we got only 38 mpg (faster acceleration, less coasting). Elevation change was minimal, little wind.