I want to get the best mileage I can from my Fit. What types of things could be done, without violating emissions laws etc, to get a bit more power and more mileage from this thing? Since I'm not looking to increase HP or Torque directly but to increase mileage, HP/Torque increases as a biproduct of a mileage increase are fine. For instance I'm going to get some lightweight wheels, something along the 10lbs per wheel range. I might even think about a 14" wheel, most likely I'll stick with the stock wheel size. So mileage and driveability improvements are paramount for me. If a CAIS and cat back exhaust fit the bill then so be it, however I would want a muffler that was NOT loud. A slight increase in db would be fine but I do not want a loud muffler on this car. My bike has long 3" pipes on it, and it's loud enough for it and the car combined So what do you think? What types of mods would be acceptable with a goal of improving mileage? Also, are there any mods to avoid? If the answer to this whole question is to leave it bone stock then so be it.

Just as an fyi, I already pay very close attention to my driving style, I watch the rpm's, I shift early, I try very hard to not waste fuel, I tend to drive just over the speed limit (65 here) so people won't be inclined to run me down on the freeway. In town etc however I stick to the posted limits and no "Jack-Rabbit" starts racing from light to light.

 

I am not sure what the situation is with these cars, I have seen some posted economy that is quite low. Constant highway (5 speed base) with the AC on or off, windows up or down, 65-80mph range, and I get 40-41. Town driving, not trying to race but not going slow AC on and off....35-38. Better than the US-EPA sticker.

Maybe the sport is worse with the extra kit on it?

 

hmnn...

I can't imagine that the Sport weighs much more with the body kit to effect mileage much, if at all unless it's creating some serious drag. I normally don't run the AC unless it's hot as hell outside and cooking me in my own juices. I'll have a much better idea of my mileage after a few tanks go through it. I'm still on the "dealer tank" so no clue really yet.

 

I am getting about the same as Spule 4. I have a base model. When I do go 80-85mph on the Turnpike or I-95 for over an hour straight I have hit about 25-26mpg. I mean it depends on weather factors also, such as wind etc. that may cause more "friction" to the ride. All in all, 20% city and 80% highway (65-70mph) I get about 40mpg on average.

I think most people will agree that having the tires at the right pressure will yield great results and also driving under 3K rpm if possible. I am also planning to get some light weight rims to see if the mpg can get even better.

I don't know if the discussion has been made yet or not, but I am still contemplating over 15" vs 16" rim/tire combination. Say I get some 11lbs 15s wid tires versus some 15lbs 16s with tires. Which one would weight less and be better for fuel economy?

 

The smaller, lighter wheels are going to be better for mileage. Which is why I'm shooting for some 10lb 15" wheels. I looked at the weights vs models and there is only 50lbs difference between the base and the Sport 5spd model. So I doubt that the body kit is hurting mileage at all. Cruising back and forth to work I see about 3100rpms with the cruise set at 67mph.

 

Well..speed and drag are factors, so windows up/AC at speed should be considered. 200+ more pounds of parts will be a factor too, not great, but a factor. Why the the donut spare came about....

Also, interesting weight savings are made on these cars. Anyone else notice anything about the headrest stems and the exhaust hangars? Not solid metal, but tube!

Herr Smeister has a good point...bigger tire = bigger footprint, greater drag. The Dunlops SP31 AS on the base cars and Sports with 15s are a low resistance design, used on some hype-brid cars. Check the archive, you can see some info I have dug up on them.

More here from Tire Rack as far as pricing but no reviews. Not sure on local dealers, Tire Rack are good from ordering many sets of tires from them. Do check price, by the time you factor in shipping, often you can get just as good a deal locally:

http://www.tirerack.com/tires/tires....del=SP31%20A/S

The other thought I had was the Nokian i3 for replacement, my past experience with Dunlop was less than good.

ALSO......he is right, check air pressure. Mine were low when I got the car (28ish) and then again a month or so later when I checked them before a long trip.

 

The biggest factor that will affect your fuel economy is YOU.

I don't own my Fit yet, but I'd bet that even racing around with your toes tickling the injectors, you should still get near or better than 30mpg. Taking your time to accelerate, choosing a median speed on the freeway (and using cruise whenever you can) can maximise that.

Having owned a hybrid (Honda Insight) which gave me TONS of feedback on efficient driving, here's a few tips:

Maintain your vehicle!! Use GOOD quality oil and filters, change them regularly. In the Fit, I'd mind the oil life readout, but I would not wait until it gets to 0%. There is NO HARM in changing your oil early (except to your wallet)

Keep your tires properly inflated! Run them a few pounds higher pressure than recommended (no much, maybe 2-5lb). This lowers the rolling resistance of the car.

Cruise in the highest gear possible. This keeps the engine revs low.

Use the cruise control OR avoid a lot of changes in speed if at all possible on the highway.

If I think of anything else, I'll post here.

 

theoretically narrower tires would decrease frontal area and increase MPG but at the expense of safety (handling and, more importantly, braking distance).

I wonder if, when piggyback engine/ignition computer system stuff comes out, something could be done to 'de-tune' the car to increase MPG. Perhaps fiddling with a rev-limiter to curb your engine speeds. I know that the car is a two valve engine below 3400 rpm and a four valve above and those extra intake valves will suck down the fuel.

In the 'mods that make the car cleaner' thread it was suggested that a less restrictive exhaust system could potentially increase MPG but those things are LOUD. (I am seriously considering running two cats an no muffler though...) I am doubtful about CAI because of its effect on warm up time and how the engine might adjust fuel mixture. Maybe somebody who knows more about that than me should comment.

 

True on the dissipation of heat......(but remember the reduced resistance)

....aquaplaning on the other hand?

 

I couldn't agree with Fray Adjacent more...

The key thing is to have a light foot in all situations. Accelerate to speed slowly and evenly. Maintain a moderate speed on the highway beacuse drag goes up as the square of speed. At 80 the drag the engine has to overcome is 1.5 times that at 65. Check your mileage after a run at 80 and then a run at 65, you'll be amazed at the difference. The other thing to do is to coast in to stops whenever possible, instead of powering up and then using heavy braking to stop at the last second. That's the difference between those that are seeing 33 and 39 on the highway. If you're going for high mileage that's what you have to do.

 

Seems like he understands the conservation of momentum driving style necessary for good MPG. He's wondering about modifications.

 

That helps a lot... try to avoid changes in speed a lot.

I do counter one suggestion: Don't take FOREVER to get up to speed. Getting to speed, and then cruising for as long as possible is a good thing to do. Not balls-to-the-wall acceleration, just get to speed quickly and stay there.

When you see a red light ahead, start coasting. If you're lucky, the light will change, and you'll still have some speed, which means you won't have to burn so much gas getting back up to speed.

 

Yeah I play the look ahead game all the time, drives my wife crazy. If I can see the lights for the cross traffic I'll coast as I get closer to the intersection and if the light goes yellow and I'm familiar with the intersection I'll coast as long as I can waiting for the Green to come. My wife smacked me last weekend cause I scared the crap out of her once heh. I managed to increase my mileage by 4mpg on average in my SUV driving like that. Rather than holding my speed and braking hard at the lights to stop. Plus it saves on everything else too when you think about it. Less tire/brake pad wear because you're not stopping hard every time either. Smooth excelleration to speed, not in a hurry but purposful, get to speed and stay there. I did a lot of research on hybrids and the driving techniques used to get the crazy 70+ mpg that some are capable of. They apply to normal driving too. I laugh at people flying by me on the freeway in their 4000lb SUV's doing 80 because I know they're going to spend $100 to fill up and they can't be getting more than 10-14mpg Now that's insane!

 

40 psi and synthetic oil combine to increase efficiency by 2-3 mpg on the highway.

 

ohh good to know, I'm planning to switch to synthetic at 2k miles so I've got a bit to go yet.

 

I think, once I get my Fit, I'll order a case of Amsoil. That should last me a couple years, at least!

 

weird that the most i have gotten out of my fit is about 38mpg, and around 35 on average.

i have a sports package and mostly drive between 75-80 on the highway and seeing about 30% of the drive below 5th gear

 

I live 15min from Summit Racing so I'll go down there and find the fluids I want when I switch. They might even have some other goodies, been a while since I was down there.