Hi. I have a 2014 Camry SE. 135,000 miles. My highway gas milage has always averaged around 31-32 mpg. All of a sudden it has dropped to 23 - 27 mpg. And the transmission now downshifts all the time. Even happens with the cruise on and going approximately 73 mph and on level road. it will downshift and the rpms will go to 3,000 rpms and sometime downshift and rpms going to 4,000 rpm. Would those rpms represent 3rd and 4th gears in a 6 speed automatic? Ironically I bought a used 2009 Venza a few years back and that is doing the same thing but I was told that is normal because it's a 4 cylinder with all wheel drive. But now the Camry is doing the same thing. No codes on either car.

One thought on this and it might sound crazy. The Camry was always filled up at a local Mobil station in town seeing that station was in route to commuting to work. The Venza has been filled at a Mobil in a neighboring town because it's 10 cents a gallon cheaper. Now that we are retired and no longer driving the commute. I started filling the Camry at the Mobil station in the neighboring town to save money. Especially with the current gas prices. And now it's acting like the Venza.

Now this is just a theory. But could the pump click off a bit later at the station in the neighboring town then at the local station causing gas to get into the charcoal canister? Buying gas at the neighboring station is the only thing that has changed with driving the Camry. Thank you for any thoughts and inputs you might have.

Ewetwo

 

Do you think the MPG is dropping because the engine RPM is now increasing or is there some other problem?

These cars have an electric torque converter lockup. Lockup is when the two parts of the torque converter are now rotating at the same speed.

There may a switch, typically on the gear shifter, that when activated has the torque converter unlock and this will increase RPM. Perhaps there is something wrong with this system. Determine if the lockup system works but using the switch.

The car may also have a button that when pressed slightly changes the gear shifting.

Over filling the gas tank can cause issues with the cars EVAP system but this typically doesn't cause any driving issues only a check engine light.

Did you check for transmission codes?

When does the car have problem, hot, cold, both?

 

Hi Joey,
The Camry has paddles you can shift with or pull the shift stick to the left and you can shift it pushing the shirt stick up or down. No button on the shift sticks. Both cars have that. It is happening all the time. Hot. Cold. I'll have my mechanic check for codes. It's going in this week for snow tire swap and new spark plugs. In the mean time I'm not going to buy the gas at the neighboring town station to see if that helps.

 

Do some experimenting to determine if the transmission is actually down shifting to another gear.

As stated when the torque converter unlocks the RPM will also increase. Here the transmission is not downshifting.

Determine if minor throttle movements cause this issue. The car has a sensor that detects throttle position which could fail.

 

oH, You can feel the car jolt when it happened. Especially when it downshifts to 3rd Gera while doing 73 mph with the cruise on. LOL.

 

Does this car have a 4 or 6 cylinder engine?

It the trans a 6 speed?

Might check MAF sensor which can cause lower MPG and apparently for the 6 speed shift issues.

 

Joey. 4 cylinder with a 6 speed automatic. Has around 130,00 miles on it. I'll clean that tomorrow. Thank you.

 

The Camry is actually at the shop. But my 2009 Venza that I bought used has always done the same thing that the Camry is doing now. So it's got to be some electronic sensor or something. I was hoping the MAF was dirty in the Venza because when I bought it. I went to change the air filter and one of the nuts in the housing was missing so it wasn't sealed tightly. So I cleaned the MAF today. Disconnected the battery when I did it. I most likely won't get it on the Thruway until Friday or Saturday so I can set the cruise and see if it still does the downshifting. I know the normal downshift on a up hill grade at 75 would expect to downshift but down to 3rd gear while doing over 75 just isn't right. The whole car just jolts when it does it. The Camry was fine until 2 week ago and then it started doing the same thing. I checked to see if a mouse built a nest in the air cleaner of the Camry and Venza but they were both clean.

 

Please keep us informed.

 

Will do.
I also read something about a speed sensor in the transmission?