On my trip this weekend, I wanted to see just how far I could go before filling up. 530 miles later (on the odo) I finally got nervous enough to stop for fuel. But I only put in 13 something gallons! I think I could have easily gone over 600 miles on this tank. But, my low fuel light came on and after staring at it for about 25 miles it made me very nervous.

Usually, my low fuel light doesn't come on until my FCD says range is in the 50's. But this time, it came on in the 80's. I wonder why that was?

One day, I think I'll put the 1 gallon fuel tank in the trunk and see if I can break the 600+ mile tank mark.

 

I regularly get to around 500 miles, have the fuel light come on, and put in around 13 gallons. According to the manual, that leaves 3-4 gallons in the tank. So I think you (not I) should try the gallon in the trunk and shoot for 600. You only need to average 35.3 mpg to get to 600 on 17 gals.

 

Yeah, but 600 in the HAH is the impressive territory!
Now that you've broken the 500 barrier, you'll get more and more comfortable going further.

The HAH very reliably lights up the idiot lamp at 13 gallons burned- I've never had it miss by more than a quart.

The most fuel I've put in was 14.8gal, and the furthest I've driven was 545miles, I think.

The mpg gage is accurate and consistent enough such that I confidently believe that as long as it says my tank average is >36, I can roll off 600+ miles and still have a 1/2gal cushion sloshing around. The only reason I haven't is the way my commute route is structured. I'll push for a 600-mile tank this tank- I'm 1/2 through and sitting at 36.8 now.

 

...because you got north of 38mpg. I recall a rumor somewhere that said Honda's FCD calculated to leave 2gal in the tank at 'zero miles to empty.' 80 miles to empty correlates pretty well with that at 38-40mpg

 

I've only found 2 or 3 600+ mile tanks in the DB, though I only scanned the 1st 20ish cars. The record seems to be GreenandBlue, though I think this was an Xcel-assisted tank...absolutely had a large amount of FASing to do this.

49.1mpg, 746 miles, 15.2gal, 80deg, 360min

Here was another 600mile tank, with mpg matching you, added by rgeiger:
39.4mpg, 618miles, 15.7gal, 70deg, 300min

So who's game to try for a summer-of-600mile-tanks?

 

Wow, seeing that others have been able to do it is encouraging.

If I recall correctly, the HAH brochure said it could go 649 miles on a tank. I'll have to dig it up to get an exact number, but the mileage was based on 17 something gallons times 37 MPG.

 

17.1 x 37 = 633, the number also used in a lot of the HAH reviews, IIRC.

Though I thought the tank was 17.2 Harrumpf.

 

Nope - Xcel didn't help me with that tank (although when I loaned him the car, he was able to get some 60mpg segments on his work commute, and he did FAS the car, use all the tricks at his disposal, etc). Pics of that are in the Share section, btw.

I did not post any of his mileage in the DB - that little gold star was purely my efforts - it was important that I made that goal on my own, as I felt it would be an unfair advantage to post his efforts with the car. (I think he got almost 900mi out of the tank when he had the car, btw - the Share pics will show what he did).

For that tank in particular, I drove (alone; I weighed < 200lbs at the time) from Northern IL to a suburb of Cincinnatti, OH and back. Straight back; I did not drive in Cincy at all once I got to my destination, and pooled with other people in another vehicle for my trips in that locale. So that was as close to a pure interstate trip as you can get. Try arguing with the uninitiated that you can't drive your brand-new fuel efficient car around town because you're working on a record tank. Suffice to say, I was looked at a little bit askance at times.

I had to stop a couple of times (not more than 3) each way to use the facilities and stretch my legs, so that time was not 'non-stop'. I also had the benefit of warm weather, trucks to draft when possible, and driving the minimum speed (posted speed limit on Interstate highways in IN is 70mph, w/ a minimum of 65; I drove even slower than that when I could safely do so). However - and this is important - I did not FAS the car, because of the known issues with re-engaging OD on a higher-speed FAS). This is pure DWL / DWB, people.

Also, I filled that tank slightly more full than usual (but not an absolute top-off, because of the charcoal canister potentially being ruined through fuel expansion).

Tires were inflated to 50lbs for that trip, given the interstate conditions (I usually ran at 38 around my locale, for reference). Xcel had them up to about (at least ?) 50 during the week he had the car, as well.

Finally, I knew per the service manual that the Navi unit is calibrated to allow about 20mi after the display reaches '0 mi' for range (it will go to dashes below '0'), and Xcel and I had had the tank down to '0', close to '0', or past '0' several times in the past. So I had trust in the display, if you will. Was near fumes as I got back to my starting point.

Xcel had figured I would break 50-55mpg on a longer highway trip, if I was very careful. Didn't quite do that, but would have, except for some traffic in the Chicago area at the outset (I took a slightly different route home and skipped over that traffic on the return).

Congrats on the 1st 500mi tank. Nice feeling to reach a milestone like that, eh ?

 

that's right- I forgot that you don't FAS, either.

I have had several 49-52mpg segments while drafting at 50-55, so actually I do believe (know) it can be done without the more far-reaching techniques, given enough runway.

FWIW, I have become a firm believer that, although DWL is a good technique, on not-too hilly stuff, cruise control + DWB will blow any other combination of (simple) techniques out of the water.

 

That's in interesting observation. Personally, I find that DWL works best on terrain that is only moderately hilly because I can only carry so much kinetic energy into a hill. Sure, I can coast down any length of hill if it's steep enough. But by the end I'm only going to have an extra 10-15mph that will only carry me so far up before I have to put my foot on the throttle to hold steady at my chosen minimum speed. Hmm...