I decided to try and achieve the highest possible fuel economy from my car this last fill up. I had to drive to Jamestown from Syracuse, NY and back for work, and I wanted to really see what the tC is capable of.

I do not have synthetic oil in the motor yet. I'm running at the factory recommended psi front & rear. The only thing I did different was cruise at 55mph, and no fast acceleration. It really is painful to drive like this, but the difference is huge. Usually I get in the mid to high 20's driving with traffic (70-75mph freeway). (For reference, the sticker on my 09 tC states 20city/27highway)

Trip A: 349.2 miles
Fill-up: 9.645 gallons
--------------------
36.21 mpg

I took a picture of the receipt at the pump, and wrote the trip mileage on the receipt after filling up. http://lindhome.com/pics/36mpg.jpg

Has anyone recorded similar results with their tC?

 

Might be wrong but I swore the tc gas tank wAs 11 or 12 gallons completely full.
With 1 gallon being a reserve.

 

^^what does that have to do with anything, he used 9.6 gallons

 

I filled up tonight because gas is pretty cheap here, and I leave for Philadelphia PA in the morning for work. But you are correct, the tC can take about 12.5 - 13 gallons if you run her dry. I was about a needle over a quarter tank left on the display when I filled up tonight.

 

It matters because he didn't say if he ran it till he was cmpeletly out....it's like me tellin u I put 2gallons in an ran 300miles.....
He filled his tank and ran his miles and stopped with 1/4 tank left doesn't mean he only used the 9gallons he put in sooo the math doesn't add up because for all he knows he used 10gallons...unless u take the gas out of the tank to see exactly how much is left...

 

Huh?

I started the trip-meter after filling the car up completely before my trip to Jamestown. The meter ran from 0 miles (full tank), to 349.2 miles registered, and then I got gas again. I was able to put in 9.645 gallons of gas, hence 36.21 miles per gallon. You divide how many gallons of gas is purchased into how many miles you drove on that fill-up

 

to get gas mileage you dont divide by how much the tank holds, you divide by how much you use. If you drive 300 miles and fill up and it takes 9 gallons to fill the tank back up, that is how much you used and you divided that by 300.

 

lolz

 

If you stop talking now, you will save yourself some embarrassment. The OP calculated it the proper way.

 

my bad then....still curious to the tank size then. ive never cared to check my mpgs...now im curious.

 

You really can't take a single-tank result that seriously. There's way too much variability in filling from tank to tank and with just one tank, you factor in the over- or under-filling of the previous and the next tanks. With one 36mpg tank your average mpg for the trip could be anywhere in the 32-40mpg range. (But still, anywhere in that range is VERY good.)

For the above reasons I log all my mileage online: http://www.fuelly.com/driver/bentheswift/tc

We've never got much over 34mpg, but we don't drive at 55mph constantly either. I would expect if you're good at driving conservatively and keep it around that speed that you could do 36mpg, but probably not much more. 31-32 on the highway at 65-70mph is what we normally see. I've logged every tank since we bought the car about 38,000 miles ago. I also use the site to log all the maintenance on the car. It's super convenient, and it's kinda fun to set mileage goals and see how the mileage responds to changes I make. If you are watching the tanks before and after it's pretty easy to pick out when you've over- or under-filled, and have a better idea of what your true mileage and cost-per-mile is.

 

that mileage sounds fine to me, before i was boosted i could easily get 35 mpg on the highway and that was with speed limits that were as high as 75mph at times and going above them.

now i can avg as much as 33mpg on that same trip but its still around 30mpg avg highway for me normally.

 

I don't see how you can get 35 mpg at 75mph. I'll drive anywhere between 65-70 mph on nothing but highway and can't get anywhere above 29mpg

 

well i do. 75 on cruise control for most of the time. auto tranny as well btw.

heres a screenshot i did years ago showing my gauges after i got back from one of my trips to tulsa, same 75mph speed limit roads. this one done after i supercharged it so it wasn't as high as when i was NA but still up there.

 

30 miles per gallon with 75mph average speed isn't unreasonable. I would guess than the 35mpg @ 75mph average was a result of one or two under-filled tanks mistakenly used to represent the average mpg. If you can sustain that over 3+ tanks in a row, I'll believe it, but that has been way out of the ballpark based on the 2 years of mileage logging I've done with our '09.

 

I average 30-32 mpg on the highway going between 70-75. I would never cruise at 55 mph, getting a extra few mpg is not worth that. lol

 

Its 14.5 gal tank.


I personally get anywhere from 26 to 29 mpg, though highway trips are pretty short to get to where I am going...never had any complaints even with 26 mpg though.

 

not it was done the exact same way i do all of my calculations. i got 35 before when i was N/A for 2 yrs and with the supercharger i get the 30,

and i got 33 mpg when i drove to vegas and back with the supercharger but that was just one trips worth of data and i am not making a drive like that anytime soon lol, im flying there next month not driving.

 

I regularly average high 30s, low 40s on my treks between NorCal and SoCal.

 

Come back when you break the 550 mark on a tank. With the A/C on for the entire tank. Without driving slow as *****. With 18s on your car.