Gas Change this Early??

**Tideland Prius** · 02-21-2006, 02:07 AM

not sure but just last week, my average for jsut over 100kms was 3.8L/100km (62mpg). After a trip to the local mountains and running a few errands in a hurry, It dropped to 4.7L/100km (50mpg) now at 340kms

DaveinOlyWA · 02-21-2006, 10:51 AM

Quote:

Originally posted by waprius@Feb 20 2006, 09:58 PM
I'm getting 47.5 today. Last tank was ~49 and the week before ~51. Had to let it warm up in the AM to melt the ice but it doesn't seem to make any difference. Had it since end of last June and been getting 46 - 52.

My theory for better mileage. Step on the gas for 1/2 mile and coast for 1/2 mile. 25mpg's 50% of the time and 100 mpg's 50% of the time. (25x.50)+(100x.50)=62.5 mpg's. I haven't tested the theory yet but thought it plausible.

[snapback]213646[/snapback]

hey great theory... crummy math.

mpg's is a measure of distance not time. in your equation, your mean average consumption will be 62.5 mpg... but considering you travel only ¼ the distance at 25 mph verses the 100 mph, you really cant expect each rate of speed to carry equal weight

besides, when i step on the gas, i usually get about 10-15 mpg...

either way, check out the Lacey Alternative Fuel Fair in May on the WA State sub forum. it will be a blast...come on over and meet us

mikepaul · 02-21-2006, 11:05 AM

Good weather down here has allowed me to go without running the heater most of the winter. Only when it's below 41 do I turn it on.

Drove to Myrtle Beach Monday to get some shoes at the Rockport Outlet. Averaged 50MPG until I hit I-20 coming back (used lowland route there) and 70MPH quickly beat it down to 48MPG. Still better than I'm used to this time of year.

50MPG with tires that don't slip in the rain is wonderful...

jeneric · 02-21-2006, 01:03 PM

Quote:

Originally posted by DaveinOlyWA@Feb 21 2006, 07:51 AM
mpg's is a measure of distance not time.
[snapback]213800[/snapback]

Yeah, don't let the consumption screen throw you off. If you did stick with your original 1/2 mile scenerio, you can never do better than doubling your gas mileage by doubling your distance.

25mi/g for .5mi and then 100mi/g for .5mi gives you:

.5mi * 1gal/25mi + .5mi * 1gal/100mi =
.02gal + .005gal =
.025gal

.025 gal to go 1 mile.

1mi/.025gal = 40mpg.

hobbit · 02-21-2006, 01:57 PM

Hey hdrygas et al -- or anyone who's got any hard numbers available
where radiator-blocking is concerned, could you summarize them?
I've finally done some initial testing of my own warm-air rig,
which brings hot air from aroud the exhaust header back to the
intake -- executive summary: NO effect on steady-state running.
http://techno-fandom.org/~hobbit/car.../results-1.txt
stemming from
http://techno-fandom.org/~hobbit/cars/warmair/
.
I'd like to see similar test results from the different approaches
to radiator/engine-compartment blockoffs, if possible.
.
I will probably do various kinds of "cold soak" tests to see delta
time in warming up, with and without the redirected intake. That
might be where any mileage improvement actually happens, which would
tie right in with the observations of the block-heater aficionados.
This hack might still be worth something after all...
.
_H*

Frank Hudon · 02-21-2006, 02:46 PM

one thing that I have noticed running "lips" like I do is that the OAT temp reading slowly climbs when I'm driving indicating that the air in front of the rad is getting warmer. Now on a Classic the inverter rad is in front of the main rad/condenser assy so the air flow across it is probably going foward thru the inverter rad. It's possible to get the temp in there up into the mid 20'sC after about 4 miles of driving. The reason I say this is because I leave open the two small upper grill intakes. So the air coming in there meets the rad/condenser and starts to circulate in a pattern like a big low pressure area in the weather systems. When it gets to this temp the ICE is at about 87C which is where the thermostat opens.

tomdeimos · 02-21-2006, 03:51 PM

Hobbit, Sorry to hear the air warmer didn't help.

It didn't work for me either last year, but I was hoping it was due to not getting it as well connected to the exhaust heat as you did.

The block heater is pretty simple. I drive 12 miles to work. With no block heater I generally get the car warm to 160 deg by the time I get to work or at least past the half way point.

With the block heater the car is up to 130 witin a few blocks, and over 160 by the time I go about 3 miles.

I estimate a 5 mpg improvement in my commute, but it can be more when warm enough to go the back way and get some battery mode on the end of the trip. (ie at temps above 32 deg or so.)

As to the engine block it is hard to quantify except to say in cold weather down below 10 deg F I can't generally reach 160 deg at all without blocking the radiator.

I adjust for conditions and try to keep engine at 160 to 195 deg F. This means I usually cover up more for 0 deg to 40 deg, and just cover the engine but not radiator for temps of 30 deg to 60 deg.

The benefit can be the same as the block heater or much more, as it all depends on speed of travel and trip length. Good economy for me requires the engine at 160 or better.

Last winter before I got the blocking good enough, I was lucky to see over 120 deg F on engine temp some days, driving 30 mph.

hdrygas · 02-21-2006, 07:24 PM

Well I have tried 3 (4?) radiator blocking techniques. First I used a piece of windshield reflector directly over the radiator. It was one of the foil on one side plastic on the other and air pockets like bubble wrap. Cut to fit all but the bottom 4 inches of the radiator. Second I used pipe foam insulation cut in half in the grill. The third (and 4th) have been several iterations of a blocker that fits on the front end mask. I tried several prototypes and ended up having one made up for me and it blocks so well that I have to unzip it around town. Pictures here http://priuschat.com/Radiator-Blocker-Mk-IV-t16197.html The earlier ones left the area over the fog lights uncovered, the new ones have plastic over the fog lights and block more air flow. I have zippers to open it up. I am still experimenting but the last one zipped up tight allows me to get to 160 F in about half the time as the previous blockers and they were roughly twice as good as no blocker. Now I am at temp with low temps in the 30's in 2 miles. With the previous blocker 4-5 miles. With no blocker at temps in low 40's to high 30's 7-8 miles of my 9 mile am commute. In the evening I am unzipping the lower blocker to keep temps below 200 F. On the freeway with both open I am running 185 to 195. I think that I am getting a 3-5 mpg boost at a minimum.

Frank Hudon · 02-21-2006, 09:38 PM

Henry keep closing down the opening till you get it to 210-215 and see if it climbs higher. My guess is no it won't, once the fan's come on it'll hold there. And no you won't do any damage. Wait till summer and you start using the A/C and watch for 225 and above, I can't wait for the CAN-view owners down in AZ NM and CA as they start reporting summertime temps. I've had 97-99C several times now and haven't heard the fans yet. That's 208F or thereabouts.

hdrygas · 02-21-2006, 09:58 PM

I don't think I have ever seen it quite that high. 209 is the highest I have seen on the freeway all zipped up. I was trying it out to see what happens. For the most part using the ScanGage last summer I got into the 190s but not higher with out a blocker of course. That has been my bench mark. This new blocker is clearly much tighter than the prototypes were. It has two great advantages faster heating but also maintaining the temperatures on cold days when pulse and glide leads to pulse cool and ICE on for most of my trip. On the coldest days in the high 30s I can't keep the car above 160 for glide and stopping at lights until a few blocks from work in the morning. That is no longer a problem. I would still like everyone in this area to keep an eye out when they pump their next tank. We get almost all of gas from one place and I am interested if they have made the switch to summer formula. If they have I would worry about air quality when we get temperature inversions and we will get them in the next weeks. I like the better mpg but not at the expense of everyone else.

02-21-2006, 02:46 PM	#16
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	one thing that I have noticed running "lips" like I do is that the OAT temp reading slowly climbs when I'm driving indicating that the air in front of the rad is getting warmer. Now on a Classic the inverter rad is in front of the main rad/condenser assy so the air flow across it is probably going foward thru the inverter rad. It's possible to get the temp in there up into the mid 20'sC after about 4 miles of driving. The reason I say this is because I leave open the two small upper grill intakes. So the air coming in there meets the rad/condenser and starts to circulate in a pattern like a big low pressure area in the weather systems. When it gets to this temp the ICE is at about 87C which is where the thermostat opens. __________________ You can quote me on this, People who drive vehicles that idle at a traffic light, are idiots. mine 2k3 avg. 5.36 for 46,915Km Best tank 4.4L per 100K 64.2 Imperial 53.4 U.S. gallon, MiniScanner, SilverStars, block heater, winter lips, in as of Oct 15, out on April 25. In again on Sept. 21st. her's 2k4 "B" avg. 6.01 for 42,317 Km Best tank 4.02L per 100K, CAN-view with OBD11 module and flashloader, SilverStars, 06 Chrome grill bar, Michelin HydroEdge, upper and lower grill blocker,upper out as of April 7, lower out on April 28. In again on Sept 21st.

02-21-2006, 07:24 PM	#18
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	Well I have tried 3 (4?) radiator blocking techniques. First I used a piece of windshield reflector directly over the radiator. It was one of the foil on one side plastic on the other and air pockets like bubble wrap. Cut to fit all but the bottom 4 inches of the radiator. Second I used pipe foam insulation cut in half in the grill. The third (and 4th) have been several iterations of a blocker that fits on the front end mask. I tried several prototypes and ended up having one made up for me and it blocks so well that I have to unzip it around town. Pictures here http://priuschat.com/Radiator-Blocker-Mk-IV-t16197.html The earlier ones left the area over the fog lights uncovered, the new ones have plastic over the fog lights and block more air flow. I have zippers to open it up. I am still experimenting but the last one zipped up tight allows me to get to 160 F in about half the time as the previous blockers and they were roughly twice as good as no blocker. Now I am at temp with low temps in the 30's in 2 miles. With the previous blocker 4-5 miles. With no blocker at temps in low 40's to high 30's 7-8 miles of my 9 mile am commute. In the evening I am unzipping the lower blocker to keep temps below 200 F. On the freeway with both open I am running 185 to 195. I think that I am getting a 3-5 mpg boost at a minimum. __________________ Belle, a Millennium Silver '04 BC #9 "Becoming one with my Prius, ICE on ICE off" Belle has been passed on to my daughter. I have a new silver Prius 08. No name yet we have just met but not been introduced.

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02-21-2006, 02:07 AM	#11
Tideland Prius Moderator of the North Join Date: Oct 2004 Location: Canada Posts: 19,633 My Car: 2010 Prius Model: N/A Package: Technology Package (Canada) Thanks: 229 Thanked 346 Times in 245 Posts Friends: 23	not sure but just last week, my average for jsut over 100kms was 3.8L/100km (62mpg). After a trip to the local mountains and running a few errands in a hurry, It dropped to 4.7L/100km (50mpg) now at 340kms

02-21-2006, 11:05 AM	#13
mikepaul Senior Member Join Date: Dec 2003 Location: Columbia, SC Posts: 1,742 My Car: 2004 Prius Model: Package: #9 Thanks: 1 Thanked 2 Times in 2 Posts Friends: 0	Good weather down here has allowed me to go without running the heater most of the winter. Only when it's below 41 do I turn it on. Drove to Myrtle Beach Monday to get some shoes at the Rockport Outlet. Averaged 50MPG until I hit I-20 coming back (used lowland route there) and 70MPH quickly beat it down to 48MPG. Still better than I'm used to this time of year. 50MPG with tires that don't slip in the rain is wonderful...

02-21-2006, 01:57 PM	#15
hobbit Senior Member Join Date: Mar 2005 Location: Bahstahn Posts: 3,630 My Car: Model: Package: Thanks: 0 Thanked 216 Times in 118 Posts Friends: 0	Hey hdrygas et al -- or anyone who's got any hard numbers available where radiator-blocking is concerned, could you summarize them? I've finally done some initial testing of my own warm-air rig, which brings hot air from aroud the exhaust header back to the intake -- executive summary: NO effect on steady-state running. http://techno-fandom.org/~hobbit/car.../results-1.txt stemming from http://techno-fandom.org/~hobbit/cars/warmair/ . I'd like to see similar test results from the different approaches to radiator/engine-compartment blockoffs, if possible. . I will probably do various kinds of "cold soak" tests to see delta time in warming up, with and without the redirected intake. That might be where any mileage improvement actually happens, which would tie right in with the observations of the block-heater aficionados. This hack might still be worth something after all... . _H*

02-21-2006, 03:51 PM	#17
tomdeimos Join Date: Feb 2004 Location: Lexington, MA Posts: 995 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Hobbit, Sorry to hear the air warmer didn't help. It didn't work for me either last year, but I was hoping it was due to not getting it as well connected to the exhaust heat as you did. The block heater is pretty simple. I drive 12 miles to work. With no block heater I generally get the car warm to 160 deg by the time I get to work or at least past the half way point. With the block heater the car is up to 130 witin a few blocks, and over 160 by the time I go about 3 miles. I estimate a 5 mpg improvement in my commute, but it can be more when warm enough to go the back way and get some battery mode on the end of the trip. (ie at temps above 32 deg or so.) As to the engine block it is hard to quantify except to say in cold weather down below 10 deg F I can't generally reach 160 deg at all without blocking the radiator. I adjust for conditions and try to keep engine at 160 to 195 deg F. This means I usually cover up more for 0 deg to 40 deg, and just cover the engine but not radiator for temps of 30 deg to 60 deg. The benefit can be the same as the block heater or much more, as it all depends on speed of travel and trip length. Good economy for me requires the engine at 160 or better. Last winter before I got the blocking good enough, I was lucky to see over 120 deg F on engine temp some days, driving 30 mph.

02-21-2006, 09:38 PM	#19
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Henry keep closing down the opening till you get it to 210-215 and see if it climbs higher. My guess is no it won't, once the fan's come on it'll hold there. And no you won't do any damage. Wait till summer and you start using the A/C and watch for 225 and above, I can't wait for the CAN-view owners down in AZ NM and CA as they start reporting summertime temps. I've had 97-99C several times now and haven't heard the fans yet. That's 208F or thereabouts.

02-21-2006, 09:58 PM	#20
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	I don't think I have ever seen it quite that high. 209 is the highest I have seen on the freeway all zipped up. I was trying it out to see what happens. For the most part using the ScanGage last summer I got into the 190s but not higher with out a blocker of course. That has been my bench mark. This new blocker is clearly much tighter than the prototypes were. It has two great advantages faster heating but also maintaining the temperatures on cold days when pulse and glide leads to pulse cool and ICE on for most of my trip. On the coldest days in the high 30s I can't keep the car above 160 for glide and stopping at lights until a few blocks from work in the morning. That is no longer a problem. I would still like everyone in this area to keep an eye out when they pump their next tank. We get almost all of gas from one place and I am interested if they have made the switch to summer formula. If they have I would worry about air quality when we get temperature inversions and we will get them in the next weeks. I like the better mpg but not at the expense of everyone else.