So I drove from Wilmington to Raleigh-Durham Int. Airport which is 125mi. I ran 89 octane, average speed was 75 mph, and 1 pax with her 2 carry-on bags. My mpg avg was 30.8mpg. I will say this, my car is 360mi behind getting the break-in oil changed. Is the L-series motor that sensitive if running with old oil? I go back to RDU to pick her back up which i plan changing oil, s2000 spark plugs, and 93 fuel to see if i see a difference.

 

What type of transmission do you have? Is it a Fit Base or Sport? What were your tire pressures? For a M/T Base freeway driving at 65mph with stock tires and 35F/32R that is 8mpg low, but for a sport A/T 31-32mpg at 75mph that is normal. Wind drag increases 33% from 65 to 75 which would lead to a 2-3mpg drop. Which way the wind blows also matters lol.

I would not worry.

 

You have an A/T and were going quickly. There's also no benefit to higher octane fuel, at least not 89.

Your car is fine, its the meaty bit in the middle hurting your economy.

 

if you're behind on the oil change, do that.
If your tires are below the recommended pressure, try putting them just a couple PSI over the recommended.

If you're fully into saving money and doing things like going past the MM, put in 0w-20 synthetic, it'll literally only be few $ more than conventional-especially if you buy it yourself and take it to the shop.

Usually, I'd say oil doesn't matter, and that's probably true with oil right out of the bottle. But if you're the type that actually goes the full oil change interval, nearer to the end, perhaps you'll eek out a small mpg gain over the worn out conventional oil, and the oil will pay for itself.

I'd skip the spark plug change...

 

Do you not see my sig? lol

 

Yes I plan on using 0w-20. I'm doing the cooler plug/93 for the extra free power. I've never had a car with weak of a motor (not complaining just saying) so it was funny seeing the car down shift a gear due to the incline of a bridge. Wimington is a city on beach so raleigh is piedmont. I see how folks in hilly parts of the country dont see 40+mpg. I was getting this early on its still 3700mi on odometer fresh. Otherwise was a great ride. Firm suspension reminds me of my s2000 14yr ago. I'll update this on the 4th of Jan. btw tire light was on too.

 

31mpg is the most my fit has achieved on the highway at 65mph I hoped it would do better than that considering I've managed to get that out of my wrx on road trips.

 

Keep it under 70mph and watch your initial throttle and you will notice an improvement in mpg. Was this a relatively flat route? if not, that is also a big culprit.

I can get 45mpg+ with cruise control and my Apex-i throttle controller set at ECO-mode on a very flat surface over a long distance. But, I really watch my throttle response and try to stay with the flow of traffic rather than constantly speeding up.

Don't bother with 93 octane, won't help you at all and is just a waste of money. I ran it for a year and saw no improvement.

 

If your tire light was on then that explains a lot and you buried the lede by not mentioning that.

While it may not make as much of a difference on a big car, small car means small changes have larger effects. Lose 5hp in 300hp car from tire drag no big deal. Lose 5hp in a 100hp car you'll feel it.

Fix your tire issue first, go the other way and put 2-3 psi extra and give it another try before passing judgement on the behavior. Your test is a bit flawed as it stands right now

 

No I didn't sorry. Usually they contain completely irrelevant information so I tend to ignore them lol. I did use a Fit Sport A/T in my explanation because I saw your profile pic and guessed, but I didn't want to assume :P.

If the TPMS light is on your hot tire pressure is below 27psi which is 5psi below spec and 7psi below a pressure that will be more fuel efficient.

I only ever rode in an S2k once but you can get the fit to be oversteerish happy with the stock suspension if you have 49FL/43FR/27R pressures that will make it feel more like an S2k. I autocross and that's the pressures that the car liked for the most grip with an oversteer bias. I used 15" wheels with 23" tires so its like having 24" tires with 16" wheels.

The A/T has higher gearing for fuel mileage so it will downshift going up hills much more than the M/T does. The M/T requires no downshift above 35mph in my experience driving in Baltimore, Maryland area which has short hills.

I'm used to cars with 35hp lol so I may have a bit more patience than most for slower acceleration.

 

First, tire pressure like has been said, if the light was on that's way too low. Honestly, the factory pressures are too low still, maybe 35-36 psi to still stay comfortable.

I don't think you'll see much efficency increases using the higher octane and plugs. I didn't, just a little bump in mid-range torque in some situations, but that accounts for very little of your overall efficiency. Most gains you will see while cruising.

Keep it between 60 and 70 mph, 70 is a brick wall. I cruise over 70 on the interstate but when I do, I don't expect better than 33-35 mpg. If I stay around 65 38-40 mpg is attainable. Even moreso drafting trucks and drafting passing cars to pass said trucks when I want. I road trip constantly and this has been my experience.

 

I agree with most everyone else here.

Tire pressure - you know what to do on this. Run it 2-4psi above recommended (to allow for Temp fluctuations)

The Fit is a Wedge and the fact that the back doesn't slope like the insight or prius means there is a decent sized vacuum that is created behind the car. The faster you go, the more impact it has so at 75mph, you are going to be way less efficient than at 60 or 65. My regular commute for years was 26 miles each way with an average speed of 45mph and the FIT absolutely loved it. Regular 40+mpg fill-ups. The minute I get out on the highway, that drops and if you add in a headwind, you'll drop even more. The fit is extremely light on torque so it requires the engine to Rev more to compensate and in turn, uses more fuel. I've also never really had good luck with cruise control vs. modulating the throttle manually. Skipping cruise has always netted me much better economy, especially with hills where the CC Engine brakes down hills and then adds more gas to maintain that extra 1mph to keep you at speed.

The fuel economy in the fit shines around 40-50mph.

~SB

 

I have a 2010 Sport AT-- going between 45 - 55 mph, I can get close to 38-39 mpg.

When my Fit was new I took a cross country trip From Colorado to NY--on the Interstates (70 - 80 mph) it averaged about 34- 35 mpg.

tire pressure makes a big difference- also do you have the stock oem tires or a different size?

 

See I would normally see 44-45mpg @65mph. It pays to live on the coast 11ft above sea level.

If I kept it under 70mph on I-40 where it's 70mph. i'd get pummeled...lol. Again the swap of a cooler spark plug plus 93 octane is not for added mpg. It's for the almost free 10hp gain.

Thank you...

 

Hello,

Hope you are well and Happy Holidays. If you want to get better mileage, drive 70 MPH or less. I use Mobil 1 0w-20 synthetic oil - suppose to help gas mileage. I inflate the tires to 36 PSI.

I have never got much more than 30 MPG driving 75 MPH.

Hope this info. is helpful to you.

Best,
yo

 

I have a Base '13 Fit, 5M tranny. I have gotten as high as 42 MPG (once) and 41 MPG (once), and will get 40 MPG at 65 MPH - especially with the cruise control on. I bought the car in Jan '14, with 4,000 miles on it. First time I made a trip, got 40 MPG. I thought I did the math wrong, didn't think the car would get that good. Worst MPG has been 30 MPG, and that is city / fwy combo.

The wife & I had to go from Phoenix to Tucson & back a few months ago, and got 36.5 MPG for both ways. That was at the 75 MPH speed limit, with A/C on, and cruise control. No hills, mostly flat with some incline. Tucson is about 2000' higher in elevation that Phx. I read this forum a lot and I think I'm very fortunate to get the MPG I do. I try to drive "normal", not pushing it too much. I'm not a fanatic about MPG, but am am always amazed at the MPG I get. What a great little car!

 

I would be happy with 31mpg.

 

I have tested my 2012 fit sport with everyrhing stock, driving 265 miles from Atlantic city to Albany NY @70m/h mostly highway, I get 38 mpg. Could have been better if i didnt get stuck for 20 min in highway because of some accident.

I agree wind does make a different on ur mpg. I didnt feel much of a wind when driving back which reflect higher mpg.

 

I note that the greatest improvement to our mileage comes when I can find straight 87 octane with no ethanol added. Rare around here.

Do the math--the best wind is no wind at all. You will never get back from a tailwind what a headwind takes from you.

Cheers.

 

Ok guys. So I didn't have time to get my oil changed but I did swing by Honda and sure enough my tires we're 26psi. So they pumped nitrogen in tires to 35psi. The nitrogen pump was neat. It pumped all 4 tires at once. I pumped 93 octane again. I'll be heading back to KRDU (airport code for Raleigh - Durham International Airport) on Sunday @1130 since her plane arrives @1330. I have to opine again on the ride. It's so firm which I absolutely love. It's funny because I passed 2 2015 Fits and they look so small but our car looks that way. Again I want to thank my fellow Fit family members for opining on my trip. I can't wait to see if the extra 10psi will make much of a difference. I live 2mi from my dealer so I couldn't compare power difference from the added psi but the ride was definitely better which is a good thing because she has light scoliosis and she was shift in the seat to relieve pressure like I have to do every 15min to let blood flow on my rump to prevent a pressure so. Yes that's TMI but we're adults right 😂. Just sharing what guys that have a spinal cord injury go through in order to drive. I hope this conclusion to my post read like I'm rambling. 😂