Problem: Over the last month my 2010 Ford Escape Hybrid has gone from an average MPG of 30 to 25.

Background: Driving habits have not changed. Tires have not changed. I get fuel from the same spot. Since having this issue I have: changed the air filter, spark plugs, and battery. The larger battery pack seems to be working fine. The engine shuts off when it should. However, when the engine is running, the MPG returned are significantly lower than they should be. I have read every applicible forum and this problem seems unique. I do not have and have not had any error codes. The weather has not changed. All my fluids are as they should be. I am extremely frustrated at this point as my vehicle SEEMS to be running perfectly, but the MPG is low. I have not changed out the fuel filter as in the 2010 it is a "lifetime filter" and difficult to get at... that is the next thing I will try though. Any thoughts?

 

Perhaps your "same" fuel station has switched its Ethanol blend? You might ask them.

 

Did you by chance use aftermarket spark plugs like Bosch instead of OEM spec Motorcraft?
Are you using Ford-spec semi-synthetic or full synthetic motor oil?

Sometimes you don't get OEM performance with aftermarket parts.

 

That's a big drop in MPG, so I'd look closely at what you or someone else did to your FEH prior to the drop in MPG. I can't see the spark plugs or any of the other things you did as a problem. What it could be that is a problem with the 2.5L engine is oil level. I have the same engine and my first oil change I used my front wheel ramps. This caused over a quart of the old oil to be trapped and not drain from the engine. I added 5 quarts of 5W-20 Mobile One oil like the manual called for and checked the dip stick after running the engine.

I'm am a serious hypermiler so I know when my MPG drops. Also, I had a '05 FEH and never had a problem using my ramps to change the oil. I know now to keep the '09 FEH level when changing to oil. Since my new oil was mixed with the old oil overfilling my engine, I drained all the oil and measured the amount. This confirmed the drop in MPG was from overfilling the engine oil.

This problem started showing up with the '10 FFH (same engine) and people were posting that their engines were smoking. Sure enough, many of them had the oil changed at the dealer prior to seeing smoke from their tailpipes. I told them to check the oil level and all of them posted back that the oil level was high. The oil level should be half way between the Low and High marks on the stick. Not on the high mark at all. BTW, the dealers were only draining some of the mixed oil to lower the level to stop the smoking.

Post back and tell us if the oil level was high.

GaryG

 

Sounds like the OP changed these things after the problem started, not before.

OP, you might want to check on the hybrid battery vent door actuator, as this is very similar to what occured with mine just a couple months ago. My mileage went from low 30s down to 27 and OBDII showed no codes, which automatically pointed me to the actuator based on others' reports of the same problem (it won't throw a code seen by a generic scanner, but the reduced mileage is a symptom).

Once I changed out the actuator my mileage immediately improved and is currently back up to 32mpg.

BTW, engine operation never changed during my problem either -- in other words, the ICE would shut off when it should, and restarted when it was supposed to, but the blend door actuator not working correctly led to reduced battery assistance, which is apparently what caused the reduction in MPG.

 

Did the 2010 FEH introduce the new "cabin cooling" method for the hybrid battery and ditch the outside cargo window vent? If so, can we rule out the blend door issue? Could the airflow into the hybrid battery be hindered causing abnormal vehicle operation? We don't have any various Scanguage X guage values to help guide us.

 

Thank you for the replies! My wife DID have the oil changed shortly beforewe had the drop in MPG. I will look at the oil level tomorrow. I have aScanguage, but no codes. I used all OEM replacement items, and I changedeverything out after experiencing issues. I am not using synthetic oil, but Inever have either.

The 2010 has the in cabin air circulation, but is it possible the air flowis restricted? There is no air filter to replace on the 2010 for the battery. Isuppose I could take the left rear panel off and see if there are anyblockages.

I already checked with the gas station, and it is 10% ethanol, and has beenfor the last three years.

 

Gary, is that also true for the 2007? Dealer always fills mine above high mark, but no smoking that I'm aware of.

 

Interesting, I didn't know about the change from outside air being used to cool. Spose I could've figured that out since the TSB shows it's only up to 2008. Thanks for the info guys!

 

I took apart the air intake, and while it could use the cleaning, there wasn't what I would call an obstruction. More importantly, when I was working on the car before, it was on my driveway which had about a 5% slope. I parked it on the street this time, and the oil was above the full mark. So I removed oil to get it to the half way mark. Sure enough, this has seemed to fixed the problem. I will report back in a week to let you know how it goes. To econoline: I didn't get any smoke, codes, or any other indication anything was wrong, just lower MPG by about 5-6 mpg. You might lower the oil level to the mid way mark and see if your MPG goes up.

Thanks agian!