Thank u for the info. I will try this tomorrow.
i had the car in since my last post. They had the car for 4 days and a tech took the car home, back and forth... I told them that I wanted them to drive the car the way I do in the city. They claimed that the driver drove city with a bit of driving on a parallel rd to the freeway and that he put 60kms on it each way which was 120k a day.
need less to say they got 400 kms on a 1/2 tank and they said that was normal... They were sitting at 7.8l per 100 k. and the avg speed was 35kms.
I found that interesting and said that it is impossible for them to be driving it in town as I have NEVER got that EVER. They told me that the cause is the "shorter in town Trips" Because, I do not drive to work everyday and that when I do go out I am going to say 15- 20 kms. The other thing they claimed is to much idling. Well I can tell you I am not in the HABIT of sitting in my car and letting it r
I took the car back and tried driving a little different, Every time I started going out I tried to use the hwy as much as I could. Gas was a bit better but the 35miles per hr started dropping. and the consumption started rising. Then I thought, This is crazy. I am adding extra time to every trip and going out of my way to try and get "good In town Gas consumption".
I since filled the car and started driving it back the way I "normally do" and I am back to the crappy numbers, In city 250kms on a full tank. and the avg speed has dropped to 25.
I had my mother try a little test. She drives her 98 Malibu 6 cyl the same way that I drive my G6. Actually she takes shorter trips. Only going to the food store and back every other day and she is getting 500kms on a tank which is 56.8 ltrs.
So there theory of it being because of Shorter driving tips is a load of BS.
I was wondering if it is possible that driving between 50k and 60k if the TCC could be burning an access amount of fuel?
I know that when I had the transmission issue that it was hitting hard and chugging around 50kms and if I was on the hwy and pressed down on the gas it would chug. That's when they replaced the transmission, But I do not have any of those issues now as far as chugging or " Hitting hard when it shifted around 50k" but am wondering if it is not consuming to much gas when being driven in that range?
I will however try the converter test tomorrow and advise.
If anyone else may have some other suggestions that would be great.
Hmmm. I know how the dealership can be, when addressing problems that are not easy to solve. The first thing out of their mouth is always, "it's your driving style" or "they're all like that" or "it's characteristic of the vehicle."
I went through a similar nightmare with Honda a couple years back. But I stayed on them with a vengeance until they corrected every single problem.
As long as it's not to your liking, keep bringing it back. I assume that you are under warranty??
Unfortunately, you may have to do a little leg work yourself, to get them headed in the right direction.
Let's check some things. You have the 3.5 V6 right?
Does your radio have the trip computer included?
What does the display show your AVG MPG @ right now?
Using the INSTANT MPG, track what your mpg is at various (steady) speeds.
At a steady 35mph, 50mph, 60mph, 70mph? I've always been very impressed with the 3.5's highway economy. At 65 you should see, atleast 26mpg on the display. 28-30MPG is what I've always seen indicated at those speeds.
In spirited, city driving. I *always* get 17 or 18mpg indicated by the trip computer. This is on *every* recent GM 3.5, 3.8, 3.9V6 I've driven. If I am more sparing with the throttle, I may see 19mpg indicated for city driving.
So I can see how city mpg could be a little low. But on the highway, these engines, with their healthy low end torque and tall gearing, really shine (rarely falling below 26 MPG AVG).
These are things you may have to do (but your dealer should have already):
Jack up each wheel and make sure it spins freely, without drag.
Check your tire pressure.
I'd replace the fuel filter.
Run a quality fuel system treatment through the gas tank.
Did this car ever get good mileage? Give it a good listen for any strange sounds from the engine and tranny. Both should be relatively smooth.
You say the dealer got 7.8lpk? Whoah! I just converted that... 30.1 mpg!! No way. In the city? That's just bs, for sure.
I got my best results with the dealer by taking the service technician on a ride with me and pinpointing each of my problems. The ride was NOT over until he confirmed that he could see/hear exactly what I saw and heard.
Verify that your trip computer is somewhat (they are rarely perfect) accurate. Pick out a test loop (near the dealer). At the beginning of the test route, reset the computer. At the end, note the mileage. We already know that you're gonna get less than the claimed 30.1 mpg the dealer claimed.
Repeat the procedure, but this time with the dealers tech driving. If there's no problem, his numbers should be considerably higher than yours. And that's with a similar driving style, driving normally, not trying to artificially raise the mpg.
But if he get's bad numbers too, pin him down on it and stay on them until they fix it to your satisfaction.
The other thing though... there's gonna be variation in every engine design. In a perfect world all G6 3.5's would get the same mileage under the same conditions. But in reality power, mpg and driveability can vary by a considerably large margin from engine to engine while being in perfectly good shape. Your particular engine may just be one that is gonna deliver low mpg. It happens.
But 11mpg is outside of any margin that could be considered normal. That's extreme. Did it get good mileage before? Ever?
Did you get this car used? Beware that there is a good chance that a used G6, may have been a RENTAL CAR in it's former life. That in itself opens up a whole can of worms. Rental cars get regular service, but they also have a hard service life.
They come off the delivery truck and go straight to the rental lot with, often, less than 2 miles on the odometer. Then they are rented and immediately taken on 500+ mile freeway trips non stop. Or they get thrashed around town. A NEW engine needs a proper break in, if it is to produce respectable mpg, power, and reliability over it's lifetime. Long trips with steady rpms is not good for a virgin engine. High rpm, high throttle is not good for a virgin engine. But this is exactly the kind of service these fleet units see. Even a regular used car may not have been treated well before you received it. Just something to thing about.
So many factors can effect your mpg. Yes, it's gonna be hard to find out what the problem is. But the dealer should acknowledge the problem AND be most helpful in resolving it.
Keep us posted.