[silverls]

Fuelly is a great tool. However, if you have not used it for every single fuel up including entering the tank the dealer put in when you bought the car then of course it's gonna be off. Your DIC is accounting for EVERYTHING so if fuelly isn't doing the same it wont be exact.

I personally did the calculations by hand for the first approx 7600miles. Using the gallons i put back in as displayed on the fuel pump divided into the mileage i had put on the car since the last fill up. And it was never more than .2mpg off. At about 7600 miles i got a fuelly account and have used it for 4 fill ups so far and it reads 1.3mpg higher than my DIC. This being because as i have driven the car more, I continue to learn how to get better and better mileage out of it. So on my 1.8 LS I have no complaint about the DIC MPG readout.

 

[silverls]

Setting the transmission in manual mode while running on Cruze control won't do diddly to improve mileage. The transmission is still using the same gear and torque converter. All manual mode does is to allow you to choose when to shift..

Correct, however it does force the vehicle to stay in 6th even on a light grade where the computer may decide it wants to shift to 5th, and you know it does not need to. In theory it could save minimal amounts of gas depending on the situation and the route.