We've owned an '09 Fit Sport Auto since Sept of last year. Not quite what we would have chosen (we strongly prefer M/T and since this is my wife's car, would have preferred the softer stock suspension), but we got quite a good deal, having purchased from a relative whose health declined to the point where they could not drive.

We've now done 5 highway trips of 1,000 or more miles and the MPG behavior has been, to say a bit, odd.

Trip 1: Done exactly at speed limit on flat land, 55-65 miles per hour. Overall trip MPG: 33.8. Summer fuel

Trip 2: Return route from above, driven identically: 33.6, summer fuel

Trip 3: Identical to trip 1, 34.0, summer fuel

Trip 4: Longer trip, from Midwest to West Coast, covering up to 12,000 feet elevation in the mountains. Owing to a certain amount of anxiousness to get the trip over with, reported speeds were 10 miles per hour over the limit, so as high as 75-80. Winter fuel. 34.5MPG

Trip 5:, the only one done by me: 1300 total miles, moderate (5,000 foot) mountains, drove like a maniac. 75 miles per hour minimum, much time spent at 85-90 miles per hour. Overall trip average: 39.3MPG

So, the faster we drive it, the better the MPG.

I'm suspecting it's due to the A/T's strong propensity to want to kick down a gear and drop out the torque converter lockout, thus revving the engine higher than required. At the higher speeds, this happened far less often.

Thoughts?

 

1) The "Stock Suspension" can only be referring to the suspension of the base model, which is identical to the Sport model except for a rear stabilizer bar. The Base model does have smaller 15" steel wheels and a slightly taller tire sidewall. If you really want a smoother ride, you could downgrade the wheels & tires.

2) I agree that your MPG have all over the place. Assuming you use the proper fill up method to calculate MPG, the only thing I can think of would be head or tail winds. My 2012 Auto Sport definitely does better between 50 and 60 than 70 and 80.

 

Indeed, my words "stock suspension" did mean the one on the base model.

I am stunned to hear that it's only a rear anti-sway bar and wheels. In fact, that would not make sense. If you start with an almost-neutral vehicle, and add a rear anti-sway bar, you almost always produce a dangerous over-steerer. I thougth I had read that the sport suspension added the rear anti-sway bar, thickened the front one, and considerably change the rate of springs, struts and bushings. I find that easy to believe: the suspension on this car is bordering on brutal - and I LIKE them stiff.

I added a rear bar, and thickened the front bar on my '97 Civ, and did not notice a dramatic change. There was a change, and it was good, but it did not change the fundamental character of the car.

I have not driven a base model '09, but we did drive base models in the 2012 model year. Compared to the suspension on our '09 Sport, I would call those base models "plush" by comparison. Dramatically different, not just a bit.

I find it unlikely that the octogenarians who owned the Fit prior to us did any suspension mods!



FFD

 

what cold tire pressure do you run with?

If you are relying on the 09's avg mpg computer, it had a bad data set that resulted in 10-15% higher mileage shown on the display than actual. 39MPG driving as you described seems unlikely regardless of the transmission.

There's a TSB (see the sticky thread at the top of this forum) on the software fix for the computer.

 

Honda has always and continues to always have stiffer springs for automatics

Part numbers are indeed different

This is why if I ever decide the need to get stock springs again, say going back to stock, I will get automatic springs for the extra stiffness. barely felt on normal driving, but they do make a difference tracking the vehicle



aside from that, the mileage may be from the honda computer learning more about you as the driver. The fuel mileage will get better bit by bit (only a small change, not massive like 45 versus 35). Even though you drove faster that last trip, it was still YOU behind the wheel right?

Footwork is actually pretty hard to change and maintain that change.

Plus hodna automatic modules actually will learn your foot and learn to lock up faster the more aggressive you drive. again, minimal on the Fit

 

Wind makes a huge difference. Once you're at speed the only resistance are rolling resistance of tires and wind resistance (and if you're looking for an argument, also internal engine friction, etc.). And wind resistance is proportional to the square of the speed. So going faster really increases resistance. But a 10 or 20 mph headwind or tailwind is a huge factor.

Also, maintaining steady speed uses less gas than varying a couple of mph here and there, that's why using cruise control saves a bit of gas.

 

cruise control on our fits sucks badly

I get better gasmileage using my foot over cruise.

Everytime you need an extra 1-2 mph to maintain speed, like going up a very slight hill, the cruise control FLOORS it to get to speed

 

Also he mentioned a 5,000 foot mountain. I'm guessing the driving mania occurred on the downhill side with all driving using the old inaccurate data maps that give 10-15% high avg mpg readings.

The last 1,300 mile trip I took I drove a casual 85mph (I75/fl turnpike to Largo) and got about 33mpg. I average 36mpg metro ATL 70% freeway 30% surface streets. The weeks I don't commute to the office the Fit sees only city driving and gets about 28mpg. The fit's a great commuter car but other Hondas will get better highway mileage (Civics, even current Accord).

 

also consider temperature and humidity... how often the a/c came on too.

and reset the mpg meter when you fill up. that can clear old data.

 

Watch it! 71 here and i have mine dropped on Swifts. Rides like a brick.

My mileage figures for the first three years was -

Mileage is 37,000 kms or 23,000 miles.

Results were 38 mpg Cdn or 31.6 US gal or 7.4 L/100 km. It does drop off some when I leave it in 3rd(I have Auto and no paddles here) in the city. Much more spirited.

 

We usually reset the MPG meter at fillup, but when we're on a long trip, we want to measure for hte trip. So, each of the trip MPGs reported started with a fillup at trip start, and reset MPG. Then, don't reset until the end. Readings of the dashboard indicator were correlated with fillup data, calculated by miles drive/gallons added.

On my 1300 mile trip the AC was used only in the southern end, which was also the faster end and higher MPG end, so it was just odd.

So far, the faster we drive, the more MPG.

====

At the end of the day, I'm surprised the vehicle's MPG isn't better. Our '97 Civ gave us approx 8MPG more, and yet had the older-tech non-VTEC engine, and weighed the same, and seemed to have better acceleration.

I'm starting to conclude that Honda didn't tune the car for max MPG, because they had two other objectives: 1) Protect what might be a fairly fragile torque converter lockup and 2) Achieve that highly-desired EPA ULEV sticker. i'm sure that's why they do the goofy throttle-blips on shift that make the "drive by wire" throttle feel so inorganic.

 

If yours has no paddles, then it didn't start life as a Sport.

When I'm 71, I'll still like a brick-like ride. But this is my wife's car, and I'm perfectly content with her driving what she'd prefer, which would be the base model with more cush.

FFD

 

We calculate MPG at each fill-up. Checked against the dash indicator, ours looks pretty decently accurate. One of the things I enjoy with any car is to see how high I can get the MPG sometimes by hypermiling. With our Fit, you're limited because the trans won't let you upshift very early, even in manual-shift mode. But, I've managed two consecutive tankfuls at 45MPG, by accelerating slower than any grandmother, allowing the car to slow down uphill, speed up downhill and staying on gently-hilly roads with 45 mile per hour limits.

The 39 at 85-90 miles per hour surprised me, but it was five consecutive tankfuls and the per-fillup calculation and dashboard meter correlated pretty well.

 

[QUOTE=Steve244;1186631]what cold tire pressure do you run with?

QUOTE]

Sry...32PSI. I personally prefer them hard as a rock, but again, it's the wife's car, so we use a little air cushion for her.

 

That's been my experience with all my cars. I can always improve on MPG if I disregard the cruise control.

 

Impressive! Sure you didn't have a 30mph tail-wind?