Don't know if anyone out there knows this, but over on the TDI forums, one guy has a 96 (97?) Passat wagon with a 25 gal tank. He logged 1400 miles on it.
Don't tell me a bigger tank is a bad idea because the cost to fill it is higher. 2 12 gal fills at $4/gal is the same as 1 24 gal fill at $4. That's an oversimplification, but the principle of the idea remains.
I'd rather go AHHHH every 800 miles instead of AH every 400.
101, check out marine tanks. A lot of those I've seen are heavy plastic, and short, so they could fit under a car without being too low. The problem you're facing is the stubborn sticking to the stock fuel gauge. Finding a tank that will accommodate the same levels will take time, assuming you've been searching since you first posted, I'd say its time to open your options up more.
Then again, the 323, protege, and escort GT all shared the same platform, but used different sized tanks that are interchangeable. There may be hope for other similar Honda vehicles, but I think you're best bet is custom fuel gauge and sized fuel cell to match.
How about a 2 gallon under car marine tank connected to the regular tank with a hose and an electric pump. Have a switch on the dash that you can flip and turn on the marine tank electric pump for 30 seconds or so- just long enough to transfer all of the fuel to your main tank (you should see the the gas gauge come up as it gets those extra gallons).
Filling the marine tank might be a pain though- unless you could reverse the electric pump and fill the marine tank from your main tank with a switch when you were pumping the main tank full at a gas station. Obviously you'd need an overflow hose from the marine tank to the main tank in case you left the pump on after it had completely filled.
So- it would take 3 hoses connecting the marine and regular tanks- one hose as a vent/overflow. 1 hose with a switched pump pumping from marine to main, and 1 hose with a switched pump pumping from main to marine.
Sounds like a lot of work.
The spoiler tank would be easy to fill at the pump and could gravity feed to the main tank, but it would get hot in the sun...
Gas right now is about $4.099 in WV, it's over $4.60 in some places. Try 50+ cents PER GALLON - that is right now. 50 cents per gallon times 20 gallons is $10.00. That's a little more than 5-25 cents per fillup as previously mentioned. MrChoi - I do NOT want to carry a loose gas can. If I can get a 25 gallon single tank that would be $12.50 per tank I could save. Yes, it would mean higher cost fillups, but I use the gas anyway. Figure in an extra 100 pounds of weight and I should only see about 1 MPG hit, if that, highway That would translate to 20 miles on a 20 gallon tank, so at 40 MPG that translates to $2, so I would like to keep the extra $8 per tank.
almightybmw - I can retrofit a different gauge in the original spot if I have to, but I WANT to have the stock gauge if I can.
Also - MrChoi - you don't know the kind of driving I do. Not endurance races, although my wife thinks so from time to time. I actually drive cross-country, and I'm finishing up making my first CRX roadworthy for about 6,000 miles per month. Once I get the super-modified HF, I should be able to drive between where I live and Los Angeles on a single tank. Sounds mighty good to me. That would be $25+ per month, so if I can get this for less than $600 it pays for itself in less than a year.
VetteOwner - I already actually put that much fuel in the tank, this stops as many fillups, and when I do long-distance driving, I use gaspricewatch.com or similar to find the cheapest prices. Try filling up in Arizona or Nevada where it's 25-50? cheaper than in Los Angeles, and you'll see some significant savings, plus have the ability to go through the whole state and back without filling up.
I am willing if I have to, to modify the trunk area, which is likely. Likely have a professional cut out a portion of the spare wheel well and put in the long-range tank, and the spare goes up higher. It means in-tank fuel pump, and something that will wire up to the fuel gauge, hopefully. My main concern is NOT weight savings, my main concern is I really don't want to have two tanks, I just want to have ONE.
If I can have the bottom cleaned up for aero I will do that also, but it's not the major concern.
I will get a larger fill neck added if I can - that could be an extra gallon.
Looking to trade for an early 1988 Honda CRX HF (Pillar mounted seat belts)
Ok. im just going to say what everyone else is thinking.
unless you have to drive 50 miles out of your way to get gas, this will only be a detriment to your FE. The extra weight will greatly out weigh the few less time you will have to stop for gas every year.
While I agree that it's probably not a practical or worthwhile idea to install a larger gas tank (unless you have some specific need to take long trips where fuel is not available), I've found that a small difference in weight does not ever produce a measurable difference in fuel economy. The only exception is in certain extra-light underpowered Hondas.
Just look at the data. Plenty of people remove weight from their cars, few credibly report FE gains. Plenty of people add weight, few credibly report FE losses. You really have to make a 15-20% difference in weight before you can start measuring FE effects.
An extra ten gallons is an extra 60 pounds, that's like having a child in the passenger seat, a 3% difference for a 2000 pound car. With the exception of a really good hypermiler in an underpowered overgeared lightened Civic, I don't think 60 pounds will make a measurable difference for anyone.