Last night I got a taste of the worst MPG my Fit has ever seen, which normally is around 38-42 average.

19 degrees F outside temp, currently running the 205/50-16s as of a month ago, car was loaded with 4 people, and cargo totaling 890lbs, and a full tank of gas.. I hit the interstate to come home from the store, set the cruise to around 71mph.. got off the interstate and looked at my mpg..... 22.3mpg average YIKES.

The little L15 not so good for hauling a total of 3600lbs worth of vehicle in the cold.

 

Once you get 8 mpg we can talk

 

Wow what does it take to get to 8?

Funny thing is, my avatar is my 119mph run, just me @ 145lbs in the driver seat and a 1/4 tank, I reset the trip computer right before the run, I got 22mpg holding WOT for over 30 seconds.

 

Running rich under a massive load with spark angle retard with really dense air will do that.

Got to love that GE8 ECU lol

22.x mpg is what I averaged in an afternoon at Elk Hart Lake (4.x miles/lap) with my 305lbs plus a195lb instructor piloting around the track on sticky 195/55/15s

 

Tire pressure is actually lower in cold weather and with the full load of people your tire pressure needs a few more pounds. 71 mph is very hard on mpg for a few reasons. The air is denser requiring more fuel and more power to go through it, By slowing down the IAT raise requiring less fuel. At that speed the engine loads are over 70 percent too which is where the engine runs richer for knock control.

 

Good post, I run around 36psi year around, maybe in general I should bump it up in the winter?

 

I just had to add air because the TPMS light came on. There was about 25 pounds in there from 35 when I got serviced. Due to the extra weight of the passengers more is required but 36 is OK and 38 would be optimal. I bet if you checked the tires at 19 degrees it would be 32 but as the tire heats up it will raise and its best to check them cold and in the shade for accurate readings.


Too much air pressure lowers your traction so you have to find a good compromise.

 

I am getting the worse fuel mileage I've gotten so far... Car is running great but a tad slower acceleration and just under 28MPG since putting 205-50-16" tires that weigh 22 lbs each... It's been just cold enough here to enhance power and throttle response and too cold to get good traction except with high performance all season tires... What I lose by having the heavier tires when accelerating from a stop is made up for from having the tires hook up at 35 mph instead of 45mph... Once rolling when traction is not as much of an issue I really miss the lighter wheel/tire setup I did have.

 

I think your car is adding more fuel for the Intake temp correction and maybe engine temp too. As the temperature gets warmer less fuel will be added from the correction maps. Because the fuel is not winterize the toluene freezes which does not vaporize as easy and causes more fuel to be injected too and you should notice a richer running car. They take out the toluene up here in the winter. There is still some but its mostly replaced by butanes.

 

It has been running on the rich side year round since installing the high boost kit and getting the reflash.. It is slower to warm up than it did also. The throttle response is great even in 3rd gear below 2000RPM.. I think the increase in rotating mass and rolling resistance is what is doing a bad number on fuel mileage because with the lighter setup I was always between 28.5 and 33 regardless of how fast I drove.. I just remembered that the defroster had been on some while coming and going around San Antonio so that would have hurt me some as well..... I must own up to enjoying the traction and ride comfort, braking and handling even on wet pavement.. The peace of mind that I now have with the beefier tires is worth the sacrifices in acceleration in fuel mileage but when summer comes around I'll be back on the 15X7" RPF1s and some smaller stickier tires.. I'm hoping to find a car to purchase I can live with in its stock form and a more comfortable ride by then.. I should have enough money to pay cash for a decent car by late April though I have been seeing some I could swing right now if I could collect a loan I made to a guy awhile back.

 

I see another car build in your future..

 

I think thats what hes tring to avoid lol

GET THAT DD, Tex!

Then finish the Fit the way you planned.

 

I think for the first time in my life I might drive a bone stock car if I can find the right one... I forgot, the Volvos I owned were stock and they were great... If you ever have one you'll see what I mean, but don't let any of your girlfriends drive it no matter how great she looks or is in the sack.

 

Wait, 4 people PLUS 890 lbs of cargo? That's about TWICE the maximum capacity of the Fit according to the owner's manual.

 

I don't drive enough to need a car for daily use... I think it would be nice to have a conservative little Nordic or German made car built by people my size for people my size... A Golf GTI or Karman Cabriolet would be great as would a Volvo wagon with a turbocharged engine, any of them with a manual transmission..... I could have the transmission and front end of my Safari cargo van rebuilt but I can have that done later if I decide I need it or our truck totally craps out.... The Euro cars just feel so nice to me.

 

Where did you get PLUS?

Read it again.. 4 people and cargo totaling 890lbs

If i had 900lbs of cargo alone in the back of a fit esp my lowered fit it wouldn't move.

 

The placement of the comma: "car was loaded with 4 people, and cargo totaling 890lbs"

I guess you meant "4 people and cargo, totaling 890 lbs." Or "4 people, and cargo, totaling 890 lbs."

I read it as 4 people. And cargo totaling 890 lbs.

Total of 890 is not so huge.

But if the car weighs around 2500 lbs, where'd you get 3600 from?

As far as mileage, going faster uses more gas, as you know- big difference between 60 and 70. And the extra weight. But a drive in one direction could've been uphill, against the wind... and if you were in Sport mode then it was 4th gear rather than 5th...

 

Man you're thinking way too much into this, was just meant to be a simple post with all understanding of why I got such bad MPG I was just posting to see what other people may be getting like said person that has gotten as low as 8mpg

The GE8 MT is around 2540lbs without fluids, I said full tank of gas also because that adds another 90lbs to that 2540lbs, now you're over 2600lbs vehicle weight, factor in the almost 1000lbs I was just rounding up, why get into such specific nit picking?

Plus I have a manual that was turning nearly 4 grand at 71mph.

 

Winter driving, loaded to the MAX will do that. Thing is it was a single 'short' trip, not really reflecting your operational average. Worst MPG I saw was in central Florida two summers ago. 33MPG with only me in the car. Incessant stop and go traffic lights every 1/4mile plus table top flat had me gunning it.

I have traveled 300miles at 70MPH turnpike speeds w/ two passengers and a 4X6 trailer hooked up and loaded w/ about 450# of wall units and seen 36MPG.

Go figure...

 

I had 2 a 67 and 71 Volvo both requiring 100 octane. You can not just buy a car and leave it alone. You have been doing this too long and there is no stopping. I bet you said that when you got your Fit too. You might not supercharge it or turbo charge it but you will put aftermarket wheels and a cold air and if its tune-able you might even play with that trying to save fuel. I meant it in a good way and if I could I would add things and play with the ecu.

Gas went up Jan 1 because of 2 reasons 1. We are exporting oil now and 2. The ethanol tax subsides we are paying. So now expect 5 dollars plus this summer and even more if the go to 15 percent ethanol.