Check Engine Light & Gas Mileage

bej11 · 12-13-2006, 10:23 PM

I bought my 2006.5 V6 2.7L Optima in August 2006 with approx. 2500miles. The gas mileage has never been better than 22 miles per gallon (hwy or not). It is often 20mpg. I habitually check the mileage all the time. I contacted Kia and they say it needs to "break in". I have over 7000 miles, and it still gets this bad gas mileage. The Check Engine Light (CEL) came over a week ago. I took it the dealer, and they said it was the purge valve stuck open and they had to order it. They reset the Check Engine Light (but, of course, will not fixed it until the part arrives). After getting back in the car, I noted the mileage and tank level (which is rather accurate on the Optima2006.5) I estimated that the while the CEL light was on I was getting 28.5mpg for a half tank. After that, I watched the tank level and estimated that it went back down to the 20mpg for the rest of the tank. (For the full tank, it got over 25mpg, the most ever & far above the 22mpgMax I'd been getting...so I'm not completely mis-estimating that half-tank.) Since they reset the CEL it has not come back on, and my mileage has stayed at 20mpg (or even worse). I tried to get my CEL to come back on by taking off my gas cap for a full day of driving (driving, parking, driving, etc....as I understand it, that should make the CEL come on.) No luck the CEL will not come back on. What's going on? Since the gas cap being off for a day does not trigger the CEL, my guess is that the diagnostic computer is not consistently working, therefore it is not picking up the purge valve being stuck and not adjusting for it in controlling the gas/air mixture... causing bad gas mileage. My guess is that when it did come on, it made gas mixture adjustments and the engine ran properly with good gas mileage. Does this make sense? No matter what, I'm not getting the gas mileage I should get. Any other suggestions?

N106FM · 12-14-2006, 11:14 AM

I bought a 206.5 with the 2.7 engine in June. I was getting 24 to 26 MPG in the begining. I now get only 20-22 MPG. I have 7500 miles on the car.

bej11 · 12-14-2006, 03:10 PM

Thanks for the mpg info. I was wondering what others were getting on their gas mileage ofr the 2.7L. I'm assuming something is wrong 20-22mpg is too far off the rating. (Pure hwy has been about 23.5mpg) I've owned multiple cars in my life, and never have I had it consistently that far off without something being wrong. I'm headed back to the dealer this weekend to get the purge valve. If I find out anything, I'll post it. (I don't have high expectations, though.) Does anyone have any suggestions for how to get the dealership to address the mpg issue?

bej11 · 01-24-2007, 11:45 PM

So that anyone reading this has an update. They fixed the purge valve with the warranty. And, they checked for any other problems. They found none. The gas mileage has remained poor. BUT...its 1 month later, and the Ck Eng. Light has come back on. When the light came on 2 nights ago, I topped off the tank. (I'll post the result of this tanks MPG when I fill the tank again.)

N106FM · 05-04-2007, 12:54 PM

I hooked up a Scan Gauge II to the car and have been monitoring the gas milage. At a steady (cruise control on) 40 mph I am showing around 22 mpg. At a steady 60 mph I show 31 mpg. I would have expect just the reverse. I suspect that the program in the ECU is not correct.

I have the 2.7 engine.

By the way I purchased the Scan Gauge II on Ebay and it displays a lot of interesting information.

Mike