Hi!

Im in the process of buying a 2013 honda fit with 140k miles from a friend; its been taken care of in its life and is very responsive in both gas and breaks, but ive noticed the mpg hovers around 26.6mpg when ive heard and seen others experience 30+mpg. with gas prices looking like theyre going to continue climbing (6.30/gallon in california) im trying to get the most out of my car for the time im spending using it. im up to date on oil changes, i just got some work done replacing a few gaskets/spark plugs/ various other tuneup activities and i wonder what i could be doing to make it even better. the AC doesnt blow cold either, if thats an issue anyones experienced and can give me some guidance on.

thanks!

 

AC could be lots of things. No freon, bad compressor clutch, bad relay, dead compressor. Bought mine with the AC not blowing cold. Was the compressor and just finished doing a full replacement AC system on it. But the easiest thing to check for is that relay. You can swap the AC relay with the radiator fan relay and verify if it is the relay.

For your MPG. I'm gonna bet most people are gonna recommend you do a valve adjustment. Other small things I could think of would be checking your air filter and maybe cleaning the mass air flow sensor. I drive my 2nd gen hard and am currently ranging around 31 mpg.

 

Is your fit an auto or a manual? For an auto, especially in city use, that’s normal. For a manual, that’s really low imo.

AC may be as simple as buying one of those recharge cans from a hardware/auto parts store and filling it back up. My Fit just needed a recharge five years ago and has been fine since.

 

Automobile efficiency isn't complicated.
1) Properly running engine and properly inflated tires.
2) Reduced weight -- don't carry extra junk in your trunk.
3) Reduced speed -- just because all your friends want to drive 10-20 mph above the speed limit, you don't have to.
4) Accelerate and decelerate smoothly and with anticipation for the conditions ahead of you. Coasting is your friend.

I have a lifetime (a bit over 5 years) average of 38.4 mpg in a 2010 Fit Sport A/T, with non-winter highway trips in the 42-44 mpg range.

 

This^^^. Exact same experience with my 2012 manual. Great advice.

 

thank you for the advice! i have a mechanic appointment coming up to see what the issue is ac wise, hoping theyll point me in the right direction. the air filters are definitely old, ill replace them and do some googling on mass air flow sensor. thanks!

 

Don't forget to check the tire pressure.
Low air pressure increases rolling resistance.
Lower MPG.
I like to keep mines at the max pressure.

 

Ditch the back seats.

 

Higher air pressure makes the tires more rigid, which can make handling feel more precise. That is, less left-right roll, or "jello" feel. It also makes the ride harsher as the tires don't soak up as much of the little bumps in the road. It also reduces the size of the tire's contact patch on the road, which slightly increases emergency braking distances. If that last thought bothers you, tires with a grippier rubber compound (something marketed as a performance-oriented tire) will more than compensate.

 

a stickier tire will also lose any potential fuel efficiency benefit from running higher tire pressures.

 

I highly doubt that. I'm not talking about track-rated racing tires that actually feel sticky to the touch - those sorts of tires typically have service lives of a few thousand miles at best. Braking and cornering traction have to do with shear force - dragging traction between the tire and road surface. During steady-state cruising, the tire compound (of a properly aligned car) experiences almost no shear forces (a tiny bit from fighting wind resistance). The blocks of tire tread get pushed straight down against the road at the leading edge of the contact patch, and then lifted up again at the trailing edge. Without adhesive stick between the tire and road, there should be no appreciable impact on fuel economy from one rubber compound over another. You could be driving on teflon-coated tires and not see a measurable fuel efficiency difference.

All I'm suggesting is a tire that prioritizes traction and handling over ride comfort and minimum noise. Tire Rack describes that split as various levels of "performance" tire, vs. "touring" tires (winter/snow tires also get a category in their scheme). Tires explicitly designed for low rolling resistance do seem to fall into the Touring category, but as I understand it, that's a feature of the tire's internal structure (additional / more rigid belting). A LRR tire with a "performance" rubber compound should be possible, just not currently made, or marketed as such.

Long-term wear is a concern with the very performance-oriented tire designs. Some people are willing to put tires that only last 10-20k miles on their toy sports cars. Look at the UTQG score - it's on the sidewall of every tire sold in the US. The number is a standardized wear-life score. A higher number will last longer. Stick to tires with 400 or higher and you won't notice a difference.

 

Please don't inflate your tires to the "max" tire PSI listed on the tire sidewall.
Inflate them to what Honda specifies, which is usually located on the door jam sticker or in the user manual.
Max PSI will be significantly over-inflated which will cause decreased braking and handling performance and increases the chance of flats and blow outs. Over inflation is not only dangerous to you but to other drives on the road (me and everyone else).

 

We seem to return to this topic pretty regularly.

The Max (Cold) Pressure on the sidewall is not over-inflated. What you're suggesting is analogous to saying that the "Use By" date on a food item really means you need to eat it by the week before that date.

It is exactly what it says -- the max cold inflation pressure for that tire as determined by the tire manufacturer. Tire manufacturers make tires. They test them to determine the best mix of lifespan, efficiency, load handling, ride quality, etc., and the manufacturer has liability if, as you suggest, their tires fail when inflated to the max cold pressure listed on the sidewall.

If a tire model was constantly blowing out when inflated to the max cold pressure on the sidewall it would: 1) result in lots of news stories and costly lawsuits, 2) quickly be removed from the market, or 3) the tire manufacturer would reduce the max cold pressure recommendation on the sidewall.

The Honda-recommended tire pressure in the door jamb is Honda's best compromise that balances performance, handling, efficiency, ride-quality (in whatever ratios Honda thinks best for that specific vehicle) without knowing what tire brand or model (performance, touring, winter) will be put on the car.

Honda's recommendation is always going to be more conservative than the one the tire manufacturer's can make for any given tire model because Honda has zero idea about the performance or safety characteristics of the tires you will put on your Fit.

Note that I'm not recommending everyone inflate their tires to the max cold pressure, but that's not because doing so is dangerous. Instead, it's because in most cases, especially for a very lightweight vehicle like a Fit, doing so will result in an unpleasant/rough ride. But, I also think that Honda's recommendation (33 psi for my 2010 Fit Sport) is too low and squanders fuel efficiency, handling, and tire life in the name of a slightly smoother ride. I run a pressure that's higher than Honda's recommendation and below the max cold pressure indicated on my tires, and I also adjust seasonally -- closer to Honda's recommendation in the winter when our bad roads are even worse and I am willing to trade a percentage of efficiency in the name of fewer shattered vertebrae.

 

Isn't the tire pressure for each vehicle determined by the weight distribution of the vehicle on each tire? Honda's conservative numbers or not, the rated MPG of a vehicle is based on those numbers I thought. I agree that you're probably not going to have a lot of risks by inflating a little past that. But if your door sticker says 33psi and you go to 45psi or 50psi because that's the MAX listed on the sidewall, that's a safety risk. Sure, maybe not for blow outs (maybe that was a little far fetched of me), but definitely risking braking and handling performance which is just as dangerous.

Inflating to max PSI on tires fitted to a 4000lb vehicle are going to be significantly different than inflating to max PSI on tires fitted to a 3000lb vehicle. Just cause the tire can handle those pressures doesn't mean the vehicle is safe at those pressures.

I'm not a tire technician or a tire engineer, but that's always seemed like common sense to me unless I've been wrong all this time (which isn't unlikely).

 

26.6mpg, that sounds really low. Any check engine lights, stored codes? Is anything aftermarket on the engine or body of the car? OEM size wheels? How fast do you tend to drive on the highway? Do you drive in a lot of city traffic? traffic jams? I average over 40mph easily in my 2009 Fit with an automatic...lastly, how many miles on the car?

 

As much as we're all discussing the fine details of tires, it's a pittance compared to the above.
Educated guess: peak cruising fuel economy is in the 40-50 mph range. It really starts to go off a cliff above 70 mph.
"Treat the accelerator like there's an egg on it." The Fit in particular has its pedal response tuned to feel sporty. Even with eco-mode turned on, the ECM tries to give you a lot of the engine's available power in that first third of the pedal travel. As an exercise (and traffic permitting), try seeing how slowly you can get the car to accelerate from a stop.

Unless you have a hybrid or full-EV Fit, the brakes are your enemy. Conventional brakes turn the car's momentum (kinetic energy) into waste heat. If you see a stop ahead, take your foot off the gas and coast to it - then you're using up that momentum on your way there and wasting less of it with the brakes.
Leave a longer following distance so you don't have to brake aggressively when the speed of traffic changes. Highway stop-and-go traffic moves in waves, like an inch worm. Breaking those waves saves fuel (yours and everyone behind you), reduces accidents, as well as driver fatigue. Try to see what's happening in the traffic ahead, and resist the urge to accelerate to follow traffic. Instead, accelerate slowly and try to match the average speed of traffic. When traffic ahead accelerates, let a large gap open up in front of you. Then when traffic ahead slows or stops, use up the gap to keep rolling and/or coast down to their speed. If you get it right, traffic ahead of you will start rolling again as you reach them. Some analytically-challenged folks behind you may get cranky when they see a large gap, but breaking the brake / accelerate waves saves them money too. If someone wants to pass, let them - they will get there exactly 2 car lengths sooner and that much fuel poorer than they would have by staying behind you.

 

Something I don't think I have said, to go along with my 42+ mpg mostly highway mileage, is I drive 55-65mph everywhere. Usually 55mph in the morning to work because there's less traffic, and in order to not be a near road hazard since everyone in GA seems to speed like the posted limits aren't even suggestions... 65mph on the way home. I had even hit low 50mpg the one week I pulled all the seats, spare tire etc. out of the car except the drivers seat, aired up the tires slightly and stayed below 60mph the whole week... So if you really got to hyper mile it, the cars can do it. (Also below 65-70mph windows down tends to burn less fuel than A/C on, above approximately 70mph the windows down cause enough drag it's actually better to use the A/C if you need it vs windows down.