I’ve done some research and based on my personal driving experiences, I’ve summarized the best practices in increasing your MPG of your Fit. I'm not an expert but an experienced daily driver of 500+ miles on a weekly basis. Cars that I've driven from my personal research are 98' BMW 540i, 04' Dodge Durango and 08' Honda Fit. As you can see I've driven various test vehicles from one extreme to another to properly experience different MPG. All vehicles driven from "Sunday School" driving to "High Spirited" driving. Additional common practices are welcome. Please feel free to post!

Driving style (Best driving technique)
Modify engine performance/maintenance (CAI, Tune-ups, etc)
Fuel type (Used of top tier gas/higher octane)

Driving Style
Impact of driving at various speeds and breaking
- Driving an average consistent speed of 55 – 65 MPH in FWY/HWY provides the most adequate MPG
- Driving average consistent speed of 25-35 MPH in City provides an efficient MPG
- Frequent and extensive breaking lessens MPG
- Coasting and letting off gas/throttle when not needed
- Driving in the proper gear keeps the RPMs down to reduce excessive fuel consumption (too low in gears can dramatically reduce MPG also)

Effects of unnecessary loads on the engine
- The more load the more the car weighs, the harder the engine runs
- Offset the car’s weight by properly inflating the tires and properly distribute the balance accordingly

Comparing cruise control to manual control
- Use of cruise control on flat straight roadways provides the most MPG than hilly terrain

Use of AC or Defrost
- City driving while AC is on lowers MPG—recommend window down instead
- Some defrost system shares the same blower of the AC system—use high heat instead to defrost windows

Benefit of drafting
- Most aerodynamic cars benefits the most while drafting behind a larger non-aerodynamic cars (Use common sense and do not tailgate a semi-truck)

Difference between fast and slow acceleration
- Slower acceleration provides better MPG than aggressive acceleration (use of VTEC at high RPM lower MPG)


Engine Maintenance/Modification
Tune ups:
- Replace spark plugs at recommended miles
- Replace spark plug cap/rotors
- Replace spark plug wires
Transmission service:
- Replace transmission fluid at recommended miles
Upgrade Factory Air Filter to Short Ram Intake (SRI)/Cold Air Intake (CAI) :
- Replacement of air filter or cleaning of SRI/CAI filter provides better intake efficiency

Fuel type
- Use top tier gas provides higher quality fuel (low quality fuel can clog fuel injectors)
- To get higher performance, use of higher octane is recommended for spirited driving, driving under heavy load and driving high grade terrain (factor in any of the above mentioned aspects)
- Use fuel cleaner once every 3 months such as Redline S1 to clean carbon build up through out your fuel system and pistons

Summary:
Slower acceleration
Reduce top speed
Proper tire inflation
Using cruise control
Proper vehicle lubrication
Correct transmission gears
Using AC only when necessary
Reducing aerodynamic drag
Removing excess weight

Thanks, Alan.

 

I would add to increase FE you can inflate tires to max sidewall psi. Which for Sport is 51psi. This gave me +2mpg.

Also using my scanguage I was able to determine that at highway speeds, the AC uses .4gph which equates to 10-15% less mpg.

 

Don't do that.

Seriously.

When your tire gets fully warm, the pressure will increase from 51psi to some number that is beyond the rated capacity of the tire.

Also, overly inflated tires reduce your ability to brake and traction in turns.

 

Not only that, but you're much more likely to get a flat if you hit a nasty pothole at such a high PSI. I wouldn't go over 45 PSI for our cars.

 

Have you been happy with the scanguage? Is it a worthy product? My husband and I both have new cars (my Fit and his Yaris) and he's considering putting one in. Any feedback would be appreciated. Thanks!

 

Thanks for the write up man. Seems helpful.

Tyler

 

nice write up, i should most agree.

yeah i noticed great mileage when cruising roughly around 63 cruise control.

i mean if you have it, use it. keeps the fuel constant and i get great mileage.

i got the best gas mileage when my car was fully gutted for race day though. heh.

 

Thanks for the feedback! I try to alternate days when I put the metal to the pedal and sunday school driving. All I have to say is that my Fit is fun as hell to drive no matter how fast or slow I drive! Best of both worlds with great MPG!

 

Ok. First Hwy trip with the Fit has me wondering what I did wrong. I drove from East Tampa to Orlando yesterday to pick up a friend who was touring Disney World. I filled up the tank right before getting on the hwy, spent the night in Orlando, and drove home today, filling up right after leaving the hwy. It was 95% hwy miles. I only got 30mpg!!! Say whuuuut? I set the cruise control for 65, rarely having to pass anyone - sometimes steady at 70. I truly expected atleast 35mpg. I am baffled now. Maybe I should stop checking the mpg...?
I can't! I CAN'T I tell you..........must...........know...........mileage
A couple tanks ago I got almost 40mpg with a 50/50 mix of driving. Crap. This car sure seems to vary alot on the mileage.

 

Questions for you: How much weight did you have in your Fit on your trip compare to when you had 40 MPG? What range of RPM and gear were you on most of the time? Were your tires properly inflated? Did you drive up on hills? Was it windy on your trip? All these play a factor on your MPG.

Weight issue is a big factor in MPG. The more weight, the more power the Fit will have to use, the more gas used.

The right RPM and gear must constantly be almost or close to optimum. Depending on your speed, specially on low gears is where it's critical. For example, 2nd gear's optimum RPM is 2500-3000. Anything over or under that runs the engine too efficient or too less efficient.

Proper tire pressure is a common sense one.

Driving on hills kicks the MPG's @$$. Don't get me wrong our Fits can handle it, but the RPM is running harder and it's not on its optimum RPM. The more hills the MPG it kills.

The wind can play a tremendous factor, specially when you're driving against it.

Hopefully, I shed some light on this matter for you. If anyone else can best explain anything I just mentioned, please feel free to do so.

 

Scanguage is the best device ever. It will help you get mpg like nothing else. I average about 40mpg going to work now(60% Highway).
CP

 

I had considered the "weight" issue. Going to Orlando it was just me, but coming back, my friend is a very large person! She's 5'10 and probably somewhere over 400 pounds (in fact I think she may have broken a spring in my couch!) **sonofabitch* So I guess coming home it would have really been like 3 (maybe even 4) people in the car. Could that have done it? I checked the tires before leaving and put them all at @43psi. Florida is pretty flat, and there was minimal, if any, wind. My Fit is an auto. so at 65-70mph I assume the rpms are fine. I don't really know what I could have done differently. I considered filling up when I got there and checking the mpg before having her in the car but I didn't.
Thanks for your input!

 

Awesome!! How complicated is it to install?

 

First, it's annoying how people refer to it as 'MPG'. "what MPG do you get?" "how can I increase my MPG"

MPG is a quantification of ECONOMY. You'd correctly say "What's your fuel efficiency like?" or "How do I increase my fuel efficiency". Just like you WOULDN'T say "How many MPH does your car go?", You'd say "How fast does your car go", since Miles Per Hour is a quantification of speed.


Second... You WON'T get any better performance out of higher octane fuel. Octane is not about power, it's about preventing detonation from compression. In a vehicle that does not require higher octane fuel, you get NOTHING from using it. In a vehicle that DOES require it, you CAN experience performance DECREASES by using LOWER octane ratings.


Other than that, the suggestions are good. I used to have a list of things I'd post on forums when people asked about ways to increase their fuel efficiency (See how I did that? I didn't say 'MPG'). I came up with the list after owning a Honda Insight for a little over a year. That car would let you know that what you're doing is increasing or decreasing your fuel efficiency.

And I always closed with this:

THE BIGGEST THING THAT AFFECTS YOUR FUEL ECONOMY IS YOU!

 

"(MPG is a quantification of ECONOMY. You'd correctly say "What's your fuel efficiency like?" or 'How do I increase my fuel efficiency')"

You must be anal retentive! Since they mean the same thing, I prefer "mpg" it's far easier to type. Are you British?

 

using a higher octane is much better for ur engine too. i felt a BIG difference switching from 87 to 91. from dead empty, it took me 28$ to fill up with premium. it may be different for other ppl tho. money isnt an issue for me so i prefer higher octane to take care of the engine and it is only a few bucks more.

also here are a few PROVEN facts to save mileage.

1. speeding in general because of wind drag increasing with speed
2.DO not overinflate or underinflate tires. just keep them at 35psi
3.maintenance on motor as stated above which is an obvious one
4.weight, for every 100 pounds u shed comes out to save 3% more gas
5.combine your trips for groceries etc. into one trip
6.flooring it!! (only on manual trans and non FI) crack open the throttle under 2000 rpms to reduce fuel pump losses without sucking fuel
7.in hot weather, open the windows in the city and just air things out. but on freeway, running the ac uses less gas than having open window drag at higher speeds
8.(for u ricers) dont add wings! they create drag and most are heavy! also try to refrain from bug deflectors
9.run engine on recommended fuel grade, theres no ECONOMY payoff in running premium in regular cars.
10.cruise more, for us sport owners, cruise control eliminates our unsteady foot from consumptive slowing and accellerating

Motor Trend has alot of good articles on fuel economy nowadays.

 

They're not quite. One is an idea, the other is a quantification of the idea.

Like the parallel of speed, you simply do not say "how many MPH does your car do".

I'm not British, either. I just actually LEARNED the English language. (that's not a personal dig on anyone, but a lamentation of the deficit of performance of our nation's educational system... the young are truly dumb because of it.)

 

You're seriously wasting your money, man. In an engine that is made to run on 87 octane, using higher octane will

Cost you more
Not get you any more power
Not burn as completely

Higher octane fuel is used to prevent or deter detonation (fuel air mix igniting prematurely when compressed) in higher compression engines.

If your engine doesn't require it, you are wasting your money. PERIOD.

Anything you've noticed is placebo. I could take your car one day, fill it with one, then a week later fill it with the other, and you wouldn't know the difference.

(It's also funny - in the things you listed, you contradict your own statement!)

 

I would recommend visiting cleanmpg.com There is everything you want to know about driving to get high FE.
CleanMPG, - What is hypermiling An authoritative source on fuel economy and hypermiling

 

You should also check the weight of everyone (plus luggage) against the rated load capacity of the vehicle. You might have overloaded the car.

With myself and a passenger, I've broken 40mpg over an entire tank doing freeway driving. The key is trying to keep it around 60mph.