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1993CivicVX 09-17-2007 03:14 PM

Boasting my two tank average
 
:D Well, can't complain. Some solid FE over two tanks of gas. First tank I posted about earlier, how the gas nozzle was in backward and overspilled--and I wasn't sure the tank was full. So, yeah, it wasn't full. So that first tank ended up averaging 67.06 over 529.82 miles (that was a false reading of course, because the tank wasn't full. And therefore the following tank which averaged 58.45mpg was also not accurate). However, the average of the two tanks does yield an accurate reading of 62.6mpg, which is an accurate reading for both tanks because it's the combined fuel for the 1026.64 miles traveled and the 16.4 gallons of gas used. I filled the tank properly this time all the way to the top (topping off a little as I normally do)

Things to bear in mind about this FE. Car has cheapo $35 Walmart tires on the front and michelin sport tires on the back. Definitely not anything close to spec tires. No mods have been done to the car.

Edit: some details on the sort of driving:

lots of pulse and glide on the hills with some engine off coasting, otherwise steady state driving at speeds mostly between 38 and 48mph. Fair amount of driving in town, which is often crowded for several minutes of 3-8mph driving.

Multiple futtsing around to get the brakes seated right and stop making noises. About 10 miles of accelerating to 50mph and then braking short to 0mph and repeat. and in reverse etc and other miscellany poor FE practices, like today when I passed 2700RPM and momentarily felt the VTEC surge to merge into traffic. The little snot-nosed hatch goes when it needs to. Oh, and I forgot to mention that I drove 75-80mph the first 80 miles of the tank from Worcester to Lee, MA on I-90 (The Mass Pike). Other than that, it was slow on the go!

Hmm... couple other little things. Filled up in Worcester MA (probably a lower elevation than the rolling hills of the Berkshires where I finished the two tanks) The route on I-90 is fairly hilly all the way including reaching an elevation of 1736 feet. But I don't think hills hurt FE much because I think they act like P&G. But who knows, maybe FE in Florida would be better.

On that note, couple notes on temps. Obviously plenty of cold starts. Last night was the coldest start. There was frost on my windshield! So we'll call that a 32 degree cold start. Otherwise driving has been mostly in the 50s-70s.

SVOboy 09-17-2007 03:16 PM

Pretty decent. What kind of commute do you have?

MetroMPG 09-17-2007 04:19 PM

Congrats! The VX is a MPG monster. I am always envious.

They're a particularly good cruiser for the "lazy" (ie. non-obsessive) hypermiler (not saying you are one). Just stick it in 5th, keep the speeds under 65, DWL a bit, and Bob's your uncle! A Metro can't touch its performance in those conditions.

1993CivicVX 09-17-2007 04:43 PM

DWL? you get used to driving slow. It's hard for me to understand how I used to drive so fast. Now when I'm in a rush I don't feel comfortable going much more than 15mph over the speed limit!

Quote:

Originally Posted by SVOboy (Post 72603)
Pretty decent. What kind of commute do you have?

It's pretty rolly hills. 27 miles one way. So I usually leave at 8am to go to school to arrive at 8:46 am. What's that for an average speed? Something like 35mph. Gonna take the scenic route tomorrow -- more hilly but very pretty--plus lots of opportunities for long engine off coastings. Although, that raises a point I want to mention. My car hasn't been so happy with bump starting of late. It will start, but then lag... no power... then go. Once, bump started, and it lagged, and didn't go! So I dropped to 3rd and no problem. But makes me wary of bump starting. Could bump starting be confusing the lean burn? Sometimes bump starts no problem - other time causes car to lurch before starting (more in lower gears) and the lag problem I just mentioned happens (I think) only in 4th and 5th gear. Also seems to be a smell accompanying the lag starts. hope I'm not damaging the engine! Anyway, with the kind of FE my car gets, like another VX owner said, I shouldn't be bothering with EOC at all.

cfg83 09-17-2007 05:58 PM

1993CivicVX -

Man that's great MPG!!!!!!! Thanks for posting you're route.

Maybe you should have a "no bump start" tank to establish a comparative baseline. But, I know it's hard to accept a lower MPG tank after getting such good ones.

CarloSW2

Gary Palmer 09-17-2007 05:59 PM

Great mileage, any way you look at it.

From what I've heard, the lean burn tends to get bamboozeled every time the ecu restarts. I thought I read it takes a pretty long period of time, on the order of several minutes, for the lean burn to kick in.
My suspicion is that your fuel pressure is bleading down and maybe it takes a couple of seconds for it to kick back on, when you bump start. The ecu turns off the pump, if the engine isn't turning over, even though the key is on.

I'd try driving your average speed, without EOC and see how it does.

omgwtfbyobbq 09-17-2007 06:09 PM

I wouldn't knock small tires just cuz their cheap. I got my $20/tire set after I found a Civic hybrid owner saying they didn't change mileage one bit. In fact, given the fuel efficient compact market, I would guess that most small tires tend to be designed for minimal Crr and wear.

1993CivicVX 09-17-2007 06:10 PM

I think given that I shouldn't be doing anymore brake testing or other FE killing stuff, a no bump start tank could still yield me low 60s. Today I parked my car at the top of the driveway, hehe. I have a kind of steep driveway and felt inspired by these two tanks. I have to say I was a bit underwhelmed by my first tank of 56mpg, but I guess that was mostly due to the fuel cleaner additive and also getting familiar with the car p'raps. I think bump starting as compensating for gas used idling at traffic lights. But, yeah, maybe I should do that... especially since the engine doesn't seem to like the bump starts. Battery could have been low... I dunno.

Yeah, other than some of the mechanical stuff still needing to be ironed out, I am real pleased with the car, especially the FE. 70mpg should be well within reach, but I don't think I will achieve that anytime soon if ever as I will prolly never do mods to my car. I don't even know if I'll ever even be able to get decent tires for it. The list of things still needing to be fixed is still quite long and the head lights suddenly don't work anymore (although the high beams still do!) But, yeah, it's a good, realistic goal.

cheers

1993CivicVX 09-17-2007 06:14 PM

Quote:

Originally Posted by Gary Palmer (Post 72643)
Great mileage, any way you look at it.

From what I've heard, the lean burn tends to get bamboozeled every time the ecu restarts. I thought I read it takes a pretty long period of time, on the order of several minutes, for the lean burn to kick in.
My suspicion is that your fuel pressure is bleading down and maybe it takes a couple of seconds for it to kick back on, when you bump start. The ecu turns off the pump, if the engine isn't turning over, even though the key is on.

I'd try driving your average speed, without EOC and see how it does.

Sounds like the gains I might be making are negligible if any if the lean burn isn't working as soon as I turn the engine back on! Yeah, I will try to control myself, but I seem to have a habit of killing the engine on certain parts of my commute. Probably causing undue wear on the car--prolly not worth it.

SVOboy 09-17-2007 06:16 PM

I think dan used to say he stopped EOCing with the VX in order to keep it in lean-burn longer...


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