Fuel Filter?
Spark plugs?

I put almost 200 miles of the 280 i got on 1 tank at highway speeds - about 75 mph. Ant still got only 28 mpg.

Is everyones computer mpg way off? It should like 30.5, but doing the math was way less.

Every time I fill up, the computer reads about 35 mpg avg and I get all excited, and then it dives. By the time you fill up, the math is about 28 - 28.5. Two full tanks thru it now.

???? What could be wrong?

 

Location? I get 35-37 mpg but I'm on coastal plain which is all flat. If you live in hilly areas the motor has to use gas to go up hill.

 

Welcome to the forums:

Need a bit more info. How long have you had the car? Any modifications to it? It looks like at this point the only info we've got is that it's a 2009 sport A/T.

First thing to check: See if your 2009's computer has been updated with the fuel economy update. The 2009 was known to read about 4-5mpg too high and there was a software fix for this. (Call the dealer and have your VIN run). It didn't increase the economy, just made the car read more accurately. (that said, mine still reads 1-2mpg too high every tank)

Get an app for your smartphone (if you have one) like MyCars for Android (iOS has similar apps) to track your economy. This will allow you to simply input a few numbers and keep track over time.

Do you have a roof rack or anything else on the outside of the car? If so, it's a Killer of economy, especially when you get up above 60mph. So is additional weight. Don't haul anything you don't need to.

Check to make sure your Tire Pressure is good. Keep it around 36psi (allows for temp fluctuations without making the tires rock hard - and they are still safe). What tires are on the car? All Seasons, Snows (Snows can hurt economy as well)

Where are you located? Cold Temps, Winter Gas, etc... can have an impact.

Try slowing down a bit. The Fit doesn't like 75mph, it's best economy is when in the 50's so once you hit the high 50's/low 60's the economy will begin to decline as speed increases. (however the A/T may be a little better in the low-mid 60's than the M/T due to gearing). On your next Highway trip, keep it at 65 and see how your economy is there. I would hedge a bet that you'd be seeing drastic increases.

The Fit is a very Fickle Car when it comes to economy and the littlest things can have noticeable changes. Combine a few together and you can see some drastic ones. My Fuel economy ranges from 25 to 40+. Right now, In VT, I'm in the high 20's

~SB

 

Bone stock. No roof rack. Brand new tires at 36 psi. Cruise control on.

I'm in NE Kansas, so moderate hills. temp was in the 80's when I got the 28 mpg. Almost all highway, at least 75 mph.

I need to check into the fix for the mpg indicator -- is there a source online? I only found 6 tsb's for the 2009, and none were for a software upgrade.

Thanks all

 

there are ur problems.

1. turn off cruise control when going up hills. let yourself lose some speed when going uphill, and regain it back when going downhill

2. 75 mph. slow down more. try to maintain 60-65.

tbh 28 mpg seems reasonable for what u do.

 

^
Listen to Ryu's advice.

I get 32.5 mpg and most of my driving is in bumper to bumper traffic.

 

How's the air filter?

 

I think 28 is excellent for 75+. I get 28-30 @80+. Mine is a 5mt.

 

Like specboy suggested, fuel economy depends on a myriad of factors: tire pressure, elevation, change in elevation, speed, wind direction, cargo weight (sprung and unsprung), drafting behind other vehicles, cruise control, quality of gas in the tank, etc. Just because the EPA says you'll get X miles per gallon doesn't really mean you'll actually get that.

 

The "At least" 75mph is your killer on economy. especially with moderate hills. The fit is powered by hamsters so it has no torque and with it's less than stellar aerodynamics, every mph over 70 you increase is going to see a significant decrease in economy.

I found that "drafting" behind someone (not right on their bumper, but just staying behind someone larger than you - like a UPS truck) helps a lot, especially at higher speeds.

The fit is an economical car, but not in every circumstance.

Make some changes in your driving style and let us know what the changes are. Oh and record a calculated mpg, don't rely on the computer.

Edit: Here's the list of TSB's and Recalls for the FIT. Look for "Display shows higher mpg..." part way down.
https://www.fitfreak.net/forums/2nd-...-info-ge8.html

~SB

 

when I put new tires on my car, discount tire aired them up to 34psi but after taking a few road trips my mpg went down 4-5mpg. then one day while checking tire pressure I saw on the sidewall that the max pressure for my new tires was 51psi, so I aired up my tires to 44-45psi and my mpg's improved.

 

This is a hypermiler's "trick" that does come at a cost. Overinflated tires will give you better economy but wear quicker in the center requiring replacement more frequently. They also give a rougher ride and decrease safety as the contact patch is smaller. Some people see that the max PSI is listed on the sidewall and assume that is the best pressure to run when in fact, it is not. The same tire could be used on a different vehicle (weighing 1000lbs more) and in turn would have a different recommended PSI rating. The Tire manufacturer designs the tire to work up to a maximum pressure rating for use on many different types of vehicles. Honda engineers who are intimately familiar with every aspect of the FIT's specs, choose the best PSI for a balance of safety, economy, and longevity.

On the OEM tires (And on my Hankook 205's) I have gotten many sequential 40+mpg tanks running at slightly above the recommended tire pressure (I run around 36psi due to varying temperature changes)

~SB

 

specboy, I thought of that so I have been monitoring it with a thread depth gauge and since I have done this (6 months) the wear has been even.

 

Air filter is clean. I'll boost up the tire pressure to like 40-44.

Last time I got 28 mpg, I did a me, the wife, and two kids . So 380 lbs total?

I did use 10w-30 instead of the 5w-20 they suggest. But could that make any difference at all?

 

make sure your max pressure on the sidewall will allow you to raise the pressure to 40-44 if not you might end up causing a blow out especially on a hot day. my max pressure is 51 and the reason I only air them up to 44-45psi to allow expansion on hot days.

 

What tires are you running? Uniform wear will vary from tire to tire. Most tires when overinflated will begin to wear a little less evenly and most importantly, will reduce the contact patch (especially on rougher roads when the vehicle is not loaded down). It may work for your setup but in general, not good (safe) practice for everyone.
With the family in the car, I wouldn't put too much additional pressure as safety should be the #1 concern. Try incremental increases (36psi, then 40 - max)

The oil you are using definitely will make a difference. on a bigger engine, the oil weight will have less impact but since the Fit has a 1.5L under the hood, using the right weight oil will make a noticeable difference. Honda Increased rated economy from the 2009 to the 2011 just by changing the oil from 5w20 to 0w20. going to a 30 weight oil means your engine has to work harder at normal operating temperature. Using a 10W also means that the engine has to work harder during start-up so by using 10w30, your fit has to work harder during warm up and continue to work harder all day long.

There's a few things still going against you achieving economy. Take care of the oil, get the pressure on the tires up a little bit, and run a few tanks of decent gas. (winter gas can be a killer). Then let us know how it's going.

~SB

 

So another tank thru - in town only, I ended up with right at 32 mpg...pretty good increase. I'm not sure when they switch to summer gas around here. Probably already did.

That a good point about the oil, for my full size chevy I dont see how on earth it could make a difference. I actually run 15w-40 - (made for Diesels) in it just because its cheaper. I need to change out the Fit with 5w-20, or less. I'll post any changes in mpg.

 

specboy, I am just offering cnb8869 advice as to what has worked for me!

 

Your gas mileage does sound a little low, but I have to agree with the other guys about 75mph+. I can set the cruise at 70mph on my 2012 Sport A/T and if the road is relatively flat can get 35-36mpg all day long. Bump it up to 75 and it will lose about 3mpg, go up to 80mph and it drops to around 30mpg. Cold weather also has an effect. When it gets close to freezing temps and below my gas mileage drops about 2-3mpg compared to temps 60F and above.

If you're on hilly interstates you'll get much better gas mileage by holding a more constant throttle setting and letting your speed vary by 10 or 20mph as you go up and down hills. Basically like tractor trailers do, of course they don't usually have a choice because they're pulling so much weight that they can't hold 70mph going up hills.

-Dustin

 

I noticed a significant drop in fuel economy with my '09 Fit when I used the cruise control. This was contrary to every other car I've owned with cruise, but there it was. Apparently, "maintaining speed at all costs" does, indeed, come with a cost.

As has been pointed out, the Fit is very sensitive to factors that affect fuel economy. Driving style, weather (rain, headwinds vs. tailwinds), road surface, tire pressure, fuel quality, even oil weight will have a noticeable, and sometimes considerable, effect.