jerrrry,

I can pretty much guarantee you did not get 46 mpg. Our Fits are extremely sensitive when filling the tank up. If you stop when it clicks you will usually be able to put in an additional 2 plus gallons into the car. That would account for your only putting in 8.7 gallons compared to 10.7 which would make your mileage about 38 mpg.

I routinely fill up with 12.3-12.7 gallons on our 10.9 gallon tank. When I drive 75 I get 34 plus mpg. If I slow to 65 I get 38 mpg. Bumping up tire air pressure may raise those numbers but then you have to factor in the cost of replacing tires sooner from wearing them out faster. I personally will run stock air pressure, have a better ride and save money on tires which cost more.

If you really want superior mileage keep an eye out for diesels when they finally make it here. I just drove a BMW 3 series wagon 2.0 liter turbo diesel in Europe for 2 weeks. A mix of back roads, autobahn, mountain passes. My WORST mileage was 40 mpg, the best at 58 mpg. This was calculated on the cars computer in US miles. I love my Fit but...

 

I think it's been said before...topping off so much fuel can be damaging to the system. The only reason why you're able to add more is because the filler neck is really long to reach the tank. There's a reason why 10.8 gal is the MAX for tank capacity. But hey, it's your car.

 

Yaya, I have heard that 1000 times before but I have yet actually seen or heard of anyone having any problems by topping up. Sounds like an old wifes tale. Perhaps it may have happened on some spicific car someware along the way.

But I have been topping ALL my cars over the last 34 years of driving VW, Saab, Chevy, Subaru, BMW, Honda, Nissan and have NEVER had an issue. Except to be driving further and stopping for gas less. So if I can go over 120 additional miles in my Fit (1500 miles a month) that is what I will be doing. After all, it is my car...

 

I'm with you, rocksnap. I've been topping my tanks for the last 30 years, no damage to report, yet... I just updated my mileage spreadsheet and my average fill over 66 tanks has been 11.21 gallons with a max of 12.6.

I've been setting my cruise control at 60mph whenever practical and my avereage for 2 tanks seems to be about 2mpg better. The slower speed isn't nearly as scary on the SoCal freeways as I thought it would be. I'll be interested to see if the trend holds up...

 

Mileage Report__2009 Sport Auto With Navi.


Tank No. _______________ First tank
Fuel ___________________87 oct. generic
Where _________________North Central Florida
Terrain _________________Flat, more or less
Elevation _______________100ft +/-
Tire Pressure ____________44lb cold
Ambient Temperature _____ Day-90 deg. +, Night 70/80 deg.
Driving Style ____________Conservative
Passengers/cargo________(Driver-150lb + passengers/cargo) 300lb Average Total
Usage __________________City-20%, Hwy. 80%(90% rural; 45-60, 10% Above 60)
A.C. ___________________90% use
Transmission ____________100% in (D), no use of (S) at this time
Total Mileage ____________419 miles
Miles this tank ____________310 miles
Gallons used _____________9.883
M.P.G. By calculation ______31.33
M.P.G. Shown on Dash_____37.0 !!!


I realize this report is somewhat verbose but all data shown is relative for comparative purposes

 

Nice post, iiyama. Keep keeping track and let us know how things are progressing after 5 tanks or so. I have found single tank readings to be less than precise for calculating mileage due to variations in the fill levels, even when care is taken to use the same station, pump and process. Welcome to the world of Fits.

 

220 days of driving. Almost equal highway/city ratio, 36 mile per day commute minimum. Bet you can't guess when I bought the Scangauge II.

 

This is likely not true. If anything, the cost of new struts might be a consideration, not tire wear.
https://www.fitfreak.net/forums/show...ht=officer.com

 

No, it isnt just an old wife's tale. check out what the government has to say...
http://www.epa.gov/donttopoff/

 

Mileage Report__2009 Sport Auto With Navi.


Tank No. _______________ Second tank
Fuel ___________________87 oct. BP
Where _________________North Central Florida
Terrain _________________Flat, more or less
Elevation _______________100ft +/-
Tire Pressure ____________44lb cold
Ambient Temperature _____ Day-80 to 90 deg. +, Night 70/80 deg.
Driving Style ____________Conservative
Passengers/cargo__________(Driver-150lb + passengers/cargo) 300lb Average
Usage __________________City-20%, Hwy. 80%(90% rural; 45-60, 10% Above 60)
A.C. ___________________50% use
Transmission ____________100% in (D), no use of (S) at this time
Total Mileage ____________751 miles
Miles this tank ____________321.7 miles
Gallons used _____________8.784
M.P.G. By calculation ______36.62
M.P.G. Shown on Dash_____40.9 !!! that's 11% dif. First tank showed 18% dif. Maby it's learning?


(I realize this report is somewhat verbose but all data shown is relative for comparative purposes)

 

Same here, except 40 years of topping and I did it today on my CRV and my Fit. My wife will fill up her Accord until the gas runs out because she hates to stop and get gas.

 

My updated history:

 

With my car closing in on 10k miles, my mileage has improved greatly since buying it. In my mix of city/freeway driving, I'm averaging roughly 29-30 MPG, with help from my ScanGauge. On a road trip back in August, I got at least 36 MPG on the tank.

One thing that helps is when you use the cruise control on a street where there is not too much traffic and you can easily set it at 40 mph or whatever the speed limit might be.

 

Jerrys calculations are accurate. I'm one of many people who I'm sure don't like to drive much longer after the warning light. In a Fit this means filling up at, or around 9 gallons consistently. It's the number of gallons used not the capacity of the tank that counts.

 

also... I have driven the fit to the point where I used 10.2 gallons. Just because 9 gallons is only needed to fill up after the warning light goes off does not mean that 1.7 is not there. It's like a reserve.

 

No disrespect but it does not matter when you fill up. When it clicks you can still squeak in another 2 gallons. When I top off like this I can go 130 miles BEFORE my gas guage moves off of being full pegged and 230-240 miles when it hits half tank. If I stop pumping on the first click I only go 50-60 miles before the needle starts moving and am lucky to go 120-130 miles at half tank. 430 miles on a topped tank, 330 miles on a stopped at first click tank. A slight difference would you say?

 

Rocksnap -

I think you are missing the point(or I am). The point is his driving techniques make up for the difference in gas used. If he stops at the first click every time then the difference will be at the pump(little variation where I live and I have data to back that up) which will yield any where for 1mpg or less difference or it will be from his driving technique and terrain/conditions.

Bye the way when I have topped off my fit I have been able to add 3 more gallons after the first click until the gas is at the top of the filler neck. One doesn't necessarily need more gas to go further just better techniques.

 

Hey Airborne, your chart and recordings look EXACTLY like my calculations over the last 6+ months, getting average 28 mpg with a few variances lower and a bit higher at times. I also have the Scangauge2 bump lol.

 

Good luck on that.
My racing partner is a full time Certified Honda Master mechanic and he cautioned me about that. The valve in the filler neck will be damage and then the evap vent container.

 

Also no disrespect, but....so yah over filling your tank does well, give you more gas to use. Though this car was not designed to hold that much more gas. It can be damaging. This is really beside the point I was trying to make. It is that when calculating mileage it doesn't matter if the tank holds 10.8 gallons if all you use is around 9 gallons, due to the low fuel light coming on. Also you don't need to over fill to get the numbers you mentioned. I have never over filled. I can get the same numbers all with around 9 gallons, with better driving techniques at 50 mph in a 55 mph zone.