Official Thread for posting daily FE updates

[krousdb]

OK, some of you asked for this, so I started a new thread for all of us to use. So here we go!

Great way to start out a new tank!

I was dreading the drive in this morning because it was dark and raining. Both FE killers due to wipers and lights on and increased rolling resistance from tires pushing water out of the way and spraying it all over. Temp was 45F. Last night I indexed my plugs and decided on a modified route to work that would cut out some FE killer lights (when I miss them). So I count 3 variables that have changed for this mornings trip, rain, indexed plugs and a new route.

Well right out of the box (garage) I noticed a difference in FE. By the time I get to the main road, about 0.2 km into my trip, my FE was 19 MPG where usually it was 16.5. Then I began the new segment of my route. Eventually when the new segment merged into the original route at about the 10 km mark, I noticed that I was about 6.5 MPG higher than my previous best to that point. At the 20 km point I was at 6.7 MPG higher, or 74.8 MPG! At this point I am at the low point of my commute so don't get too excited im telling myself. Now the merge onto I-79 and I duck in behind a fuel tanker and draft at 55 MPH, ASI showing 20-30 MPH. At the 30 km mark I am exiting I-79 and am at the high point of the commute, 61.9 MPG. The final 10 km leg has 10 stoplights and I made 5 of them. I cruised into the parking lot at 63.68 MPG which beats the old record of 62.75! The trip length is slightly shorter so the total fuel used was .384 gallons beating the previous record of .392.

So I'm sitting here wondering, WTF? It was raining, which in my experience is detrimental to FE and wind wasn't really a factor. On the downhill ign off segments, speeds seemed to be better than normal. Usually I take a hairpin curve, engine off and exit at about 35 MPH and coast for a mile or so to a 25 MPH speed limit sign at about 27 MPH. Today I took the curve slower, exiting at 32MPH and was still at 30MPH when I got to the 25 MPH sign. ASI showed same as the speedo so no tail wind.

I have heard some Prius and Insight drivers say that they notice an increase in FE with very light rain but could never prove it definitively. I can't prove anything at this point but what i know for sure is that starting a new tank this way is very satisfying. Mehbe the indexing helped? Mehbe the new route? We shall see on Monday which is supposed to be cooler but dry. Thunderstorms and wind for tonights drive, but 63F too. Maybe I will be surprised again?

[kickflipjr]

Drafting in the rain...

Your one crazy hypermiler!

[krousdb]

Doh! I thought of possibly a 4th variable.... I might have gotten the summer gas formulation yesterday! That would be an increase of 1.7% in energy content per gallon. Apply 1.7% increase to the 62.75 MPG and you get 63.87. Hmmmm.

[SVOboy]

Hmmm, I dunno sir, mehbe it's the plugs! How was the drive home, y0? I wish I had daily updates, though I will start a thread on today's issues.

[krousdb]

Well the storms held off and the weather was perfect. 72F, dry and a nice tailwind, 62.0 MPG on the way home, another record for me. I can't think of any better conditions for FE. I think this is the wall for the drive home, 62 MPG. Still room for improvement on the way to work, warmer temps and dry roads for one. But Not much more to squeeze out there either. From now on it's Built-in FE Mods. Wheels/tires first, then CX tranny and CX IM/TB. Im running out if things in my bag of tricks.

[SVOboy]

Haha, let's not forget about the engine swap that gets 30% better epa ratings than your current engine.

[krousdb]

When you get your VX installed, let me take it for a drive. If I can coax 80MPG out of it then maybe that will be my final mod.

[SVOboy]

I left a note on a real vx yesterday asking about for sale, was planning on buying it and giving it to you,

[krousdb]

My wife would kill me if I got another car. I would have to do a transplant to the del sol. With your help of course. I wouldn't have a clue what to do.

[SVOboy]

No point buying a parts car for an engine you can get for free! It's basically plug and play, to be perfectly honest, everything is the same,

Just add a wire here and there.

[thisisntjared]

the vx engine is a little more complex than that. it has the 5wire o2 sensor, vtec, and it has the exhaust recirculation valve. vtec wiring and extra o2 wire are not big deal. however the egr valve... i dont know what to do about that...run a p28??

[SVOboy]

EGR can get smacked off easily if need be. I imagine tune dan's current chipped p28 for the d15z1 or run the stock ecu.

[thisisntjared]

if you run the stock ecu you lose vtec and in that case it would just be easier to have the bulletproof d15b8.

[SVOboy]

Stock ECU for the d15z1, silly!

Anyway, 12valve z1 > 8 valve b8.

[thisisntjared]

aaaahhhhhh

DUUUHHHHHRRRR!

for lowend the b8 and z1 are about the same though, the z1 is just more revvable

valve count alone doesnt matter, you cant forget valve size.

[SVOboy]

I know valve count doesn't matter alone, but the z1 hits 97 ft/lbs of torque at 2k rpms and the b8 hits like 82 or whatever. The z1 is pretty damn torquey.

[thisisntjared]

show me the dyno graphs!!

also the z1 has a 9.3:1 cr while the b8 has a 9.1:1

[SVOboy]

These are ctq numbers and not wtq!

[thisisntjared]

then show us your sources. i have never found the advertised torque of the z1 at 2000rpm, only at 5000. i only come across the peaks.

[SVOboy]

Fine fine, hold on.

EDIT: I take it back, it makes the power higher according to one place. I can't find my original link but this second one double contradicts the first, so later I'll just try to find something good that agrees with someone and we'll see.

[JanGeo]

Trip from Newport RI to Stanford CT and back 280 mile trip yesterday at night in rain got me 40.1 mpg there and 41.3 back doing 60-65 and I try to get behind a bigger vehicle or a line of vehicles - if the line of vehicles is big enough they get the air moving your way and it greatly reduced drag. I was going 65mph and getting 55 mpg for a while behind a tractor trailer truck. I also noticed that my terminal speed going down the Newport Bridge was 53mph and it used to be 45mph . . . I still could not coast all the way to the exit ramp with the xB but I have with the Geo . . . I also noticed that a wet road yields better gas mileage than under heavy rain conditions . . . if you think about it a gallon of water hitting the car is about 8 lbs that you have to provide energy to to get it up to the speed that you are traveling and a gallon can be hitting the car in less than a minute if it is raining heavy.

[krousdb]

First update after new HX wheels and Insight LRR tires. It was dry but cold this morning, 32F. It took awhile for the engine to heat up, maybe because I have the vent open on my grille block. I took the very latest route, the one that elimninates 4 stop lights. While I did make a few hypermiling mistakes, I had a pretty good trip to work at 66.23 MPG. Previous best was 63.68 at 45F and raining. There is definately some room left to get closer to 70 when the morning temps get back into the 50's. Tonight's drive will be sunny and in the 60's.

Edit: Current tank, 165 miles, 62.94 MPG

[Compaq888]

are you using an engine block heater?

[krousdb]

Yup!

[SVOboy]

Jealousy! I need my superMID!

Anyway, the manual would be good too,

[MetroMPG]

a pretty good trip to work at 66.23 MPG

and the understatement of the year award goes to... envelope please....

krousdb! (yaaaaaaaay)

seriously, nice numbers.

[SVOboy]

Haha, what was the one trip he got around the park or whatev, 83?

[krousdb]

Drive home was 62.91 MPG, the previous best was 61.97 in similar conditions. I think I have hit the wall here for the drive home. I hope to improve on the drive to work tomorrow however.

[krousdb]

One red light can make a huge difference.

Today was not much warmer than yesterday, 39F vs 32F. But since I am still learning the nuances and limits of the new tires and route with fewer stoplignts, there is still room for improvement over the 66.23 MPG from yesterday. I started off well this morning, beating yesterdays results for the first six of eight milestones during the trip that I track trip FE. By the mid point of the trip which is also the lowest elevation, I was at 82.3 MPG vs 77.6. By the time I got to my next milestone at the top of the hill I was down to just a 1.6 MPG advantage which would extrapolate to a 67.8 MPG trip. But then the worst thing that could happen, happened. The light at the bottom of the hill turned red due to a car from a side street pulling up to the light. I make this light 95% of the time, but this time I had to hit the brakes hard from 50 MPH on a downhill and then start from a stop when the light turned green. A huge waste of momentum that left me with a 65.0MPG trip. The one light knocked me down by 2.8 MPG!

Looking at my route options again. A variable like missing that particular light will invalidate any testing that I plan to do.

[krousdb]

What a beautiful day for a drive! 72F, sunny and 5-10MPH southerly wind. So I decided to take the top off. Damned the aerodynamics I say! Just for good measure I rolled the rear window down all the way.

Woot! 65.45 MPG! That is another best for the trip home by 2.5MPG and the first time that my return trip was higher than my drive to work. Today's round trip was 65.23 MPG.

Current tank, 240 miles, 63.47 MPG.

The tires seem to be breaking in nicely. I read something over at tire rack that says it takes several hundred miles (or was it 1000?) for tires to shed the oils that are used to release them from the mold. I havent had any more understeer problems and am slowly taking corners faster to find the limit. The tires are much quieter than the Kumhos and even though they are 12PSI higher, they absorb the bumps much better. Smoother, quieter, better MPG (guestimated at 2-3). I can live with that just fine. Maybe I will get another 1 or 2 MPG when they fully break in. I am happy with my investment and the look of smaller tires and the HX rims is really growing on me. Anyway after my MPG stabilizes i will swap tires again to see how much it effects FE. Should be interesting.

Anyway no more updates until next Tuesday for the del sol although I will be online. Im off to Myrtle beach with the family for spring break. We will have the prius but in deference to the family who just wants to get there ASAP, I will be driving blindingly fast, approaching 75MPH at times. Hoping for 48MPG in the fully loaded Prius under those conditions. And if they make me turn on the AC, it goes downhill from there.