i just wanted to find out the avrage milage you get in the cts
i just got mine my is about 12.5 on the instument

DI, combined city/highway driving averages about 21 mpg. Have owned it since last August.

I've averaged 20.18mpg over the last 3293 mi. Includes about 3.5 all city tanks, and 2-3 all highway tanks. The rest are all fairly mixed, but mostly city. Calculated by milesdriven/pumpedgas. I think the DIC is a little optimistic.

Last two tanks after going over 1000 miles........25.97 MPG (about 80% expressway driving) last tank.....24.31 MPG (about 50% expressway driving). These figures are actual gallons per fill vs actual miles between fill. I have the DI with manual trans.

I drive my car pretty conservatively most of the time, and typically have a pretty good mix of in town highway driving. I've ranged from about 20.5 - 23, depending on the mix. I honestly don't see how anyone is getting 24-25 unless it is all highway mileage. City driving knocks it down awfully quickly.

My car is a DI, btw. One factor to consider is if you live where you run 10% ethanol (thats all we have in Houston). That makes a noticable difference for the worse.

been 75% hwy the last 2000 miles. Averaging 23.7 figured maually.
DIC shows about .5 Higher
All gas has been w/10% moonshine.

been 75% hwy the last 2000 miles. Averaging 23.7 figured maually.
DIC shows about .5 Higher
All gas has been w/10% moonshine.

Now I know why your CTS cannot keep the stright line - it was the moonshine! :)

My CTS is still very low mileage since I only recently took delivery. I have filled up twice at the 1/2 tank level (resetting avg MPG each time) and the DIC showed 23.9 for one and 23.7 for the other fill; my calculation was 23.6 both times so it is pretty close. I probably have the perfect route for good MPG because my commute is 25 miles one way mostly over 2 lane rural roads (55 MPH posted, 62 normal speed) with only 4 stop lights and 2 stop signs on the route. For comparison, my large 4WD diesel pickup does about 19.8-21 on the same route (depending upon whether using normal or winterized fuel) which is also very good mileage for a large crew cab pickup.

One oddity I notice on the CTS is when instantaneous MPG is displayed it has more rapid variance than other GM vehicles I own/have owned. I am not sure if the other vehicles use more damping for the instant figures or if the CTS is truly odd in its rapid variance. For example today running 62 on a level road with near calm winds it typically shows around 32-34 instantaneous but with rapid, brief jumps down to as low as 22 and as high as 38. A/C was not running so I am not sure why the sudden changes unless it is just an artifact of the measurement and/or display algorithm.

I have a 3.6DI automatic with almost 10,000 miles on the odometer. With a mix of rural, interstate and city driving, I'm consistently averaging between 22.5 and 23.5 mpg. I calculate this with the fuel receipt and compare with the DIC reading--the difference is +/- 0.3 mpg. I use only 87 octane.

I am getting 20.7mpg---average speed 35mph. 6700miles on odometer----3.6di Awd

AWD DI auto.

Mainly city driving, a few trips to the airport on the tollroad. I consider myself a pretty normal driver, rarely more than 5MPH over the speed limit and don't race off the line at stop lights. Been doing a test between regular and premium fuel. Only top tier gas (conoco and shell):

497 miles using premium = 17.8
535 miles using regular = 18.2

Car now has a little over 5,000 miles. Would like to be getting higher MPG.

~6000 miles on the car using regular with the DI. Probably 75% "city" driving and the DIC says 18.5 mpg. I've done a road-trip to Boston and Baltimore from NW NJ and got great highway miles. Now only if I can do more highway miles in my normal routine.

i just wanted to find out the avrage milage you get in the cts
i just got mine my is about 12.5 on the instument

You must be flooring the gas pedal to get 12.5 avg. I am an aggressive driver & get between 16 & 18 most of the time. I drive the base engine with AWD