Gas Change this Early??

strange as my last tank was one of the better tanks I've managed in a long time, like last fall. 48.3 US mpg. For a Classic not too shabby. I knew it was going to be right up there because of the mileage (Km's) and the amount of bars on the gauge. But it's cold and summer fuel doesn't start for another couple of months. So I don't have an answer but have noticed it also.

 

must just be you guys.

still crap here... almost busted through 48 mpg but decided to fill up tonight. and i'm ensured DH won't drive it until i've put on at least 100 miles... so that's an immediate tank mpg boost h34r:

 

well mine is about 3 mpg higher than normal... but still 5-7 mpg lower than the summer numbers. and it has been at least 10-15º colder than normal

 

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.

 

you going to the fair in Lacey??

 

Ah, if only it worked that way. Actually the formula is 1 / ((1/25 x .50) + (1/100 x .50) ) which is 40 mpg. Darn. 40 mpg ain't very good mileage for a Prius. Think "gallons per mile". The Canadians with their liters per 100km have an easier calculation for this example.

Here's another example, this time in terms of miles per hour. Abe drives around a 1 mile track at 60 mph. Bob drives half way around at 30 mph. How fast does Bob have to drive to catch Abe at the finish line? It's not 90 mph. It's.... a secret! I'll never tell!

 

Mine is getting better but only because its been drier for the past few days. I've gone from 48 to 52.

MtnTraveller: Where is the finish line? If Abe already has driven around the track hasn't he already gone through the finish line?

 

all of you guy's better show at the fair! We could possibly force the B5 and E85 vehicles to a different parking area. It'd be like a show and tell for hybrids.

 

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

 

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...

 

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.

 

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/cars/warmair/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*

 

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.

 

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.

 

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.