Fuel with ethanol lowers available BTU & does affect MPG on most cars. If you got a new software update without your knowledge it might affect actual MPG, or perhaps just the reported avg. is now lowerdue to software....be sure to verify real mpg over a few tank refills.

 

I only have a HCH-I, but was having some issues with the SOC and finally just rebooted the car. Pull the battery terminal for about 15 minutes, make sure you have your radio security code handy, and then hook it back up and take your baby on a nice mellow drive until the SOC is showing fully charged again.

As for your drop in mpg, hard to say, but sure sounds like they did something wrong on that last service. The air cleaner could cause a problem if dirty but it would gradually get worse, not just drop like it did. BTW, for the price of a air cleaner element , I replace mine every 10 to 12k miles. Not the 30k miles that they recommend.

Hopefully they are able to correct the problem.

 

A couple of things... first, I hope the dealer can figure out the problem, but it may be unlikely that they will... cross your fingers though!

As for the sudden drop in the SoC, there are several posts here at GH. The most recent one is in the General HCH forum. Its more than likely not a short in your case. I'm surprised it has only happened to you once in 18k miles, as it has happened to me at least 5 times or more in my 18k miles. It is known around here as the SoC recalibration. The SoC doesn't know exactly how much charge is in the battery at all times... it's an estimated charge. What the system does every now and then is a recal on the battery pack with the SoC, but it happens at random times. I posted in the thread here: https://www.greenhybrid.com/discuss/...tml#post176496 , but you can read through the whole post to see what others say about it as well.

One other thing that others have mentioned in this thread is that maybe it is just your mpg display that is off kilter. A manual calculation is in order to see what your mileage is based on your fillup gallons/miles driven. Some have done a system reboot on the car by disconecting the negative terminal from the battery for 15 minutes, then reconnecting it. Since you said you had a software update done, they may not have rebooted the system after they did it at the dealer. Think of Windows and its updates... 95% of the time a reboot is needed to make the updates work properly with the OS. NOTE: You will need to have your radio code to put back in after disconnecting the negative terminal for so long.

I am always afraid to bring the car to the dealer and have it come out a different hybrid. I would always hope that the car runs better after servicing, but that's not always the case. I do all my own A1/B1 oil/filter changes and air filter/cabin filter changes. I may even do the CVT fluid change myself. Anything to stay away from the dealer if at all possible, and save some $$ as well doing it myself. I want to bring it in for the camber issue and other <recall?> issue with the grease or something possibly dripping on a light (it is in a thread on the forum here), but don't want them to do some unknown software update in the process that will affect my assist/regen as I have heard some have had after an update like that. I love my HCHII the way it is!

 

My 2007 has also shown a 10 mpg (ImpGal) drop from the same time last year. We've had multiple problems with it since we bought it.

We had the rear camber fix, and they replaced 2 tires with that one. We've always had handling problems, especially in the winter in bad road conditions. When we hit a certain kind of bump, you can feel the car "twist" and steer right. The car pulls slightly to the right.

They replaced the tires with another type of tire, so now we have 44 PSI max tires on the rear (the original ones) and 55 PSI max tires on the front.

The MPG meter will sometimes start jumping from 4-5 bars to almost max repeatedly for no apparent reason ie. we are going down a hill or on a straight away.

We are currently getting the yellow regen error light on the dash, about once or twice a day - its in the shop as we speak.

Thanks for the tips, anything else we should try besides tire pressure and an air filter?

 

I'll bet someone put 10-30 oil in your engine? H

 

I don't know I'll ask them. Will that cause that much of a drop?

 

Wow, 55 PSI max rear tires? Doesn't sound like they put Low Rolling Resistance (LRR) tires on as the replacements. The LRR are softer tires and shouldn't have that high of a max PSI sidewall rating! I'd lookup the make and model of the tire and see if it is LRR. I've seen people around here say they've dropped quite a few mpg when they replaced their tires (under normal wear and tear) and went with inexpensive costco tires or something like that. LRR tires are not cheap.

There are a lot of posts on GH about the "iFC samba" which sounds like is what's happening with the conditions that you've stated.

Try to pull a few things off the shop list so they can focus on things that are wrong. Find the specs for the alignment here at GH (I've seen them posted) and bring them to the shop and have them align the front correctly. The yellow regen error light should be their main focus out of all the problems you've described... the rest seem to have "fixable" solutions.

 

10% Ethanol blended gas did drop my mileage by 10%. Missouri is one of the few states that have mandated all low and mid grade fuel have 10% ethanol. They also earlier repealed the state requirement to label such fuel sold as having 10% ethanol. I was frustrated to all of a sudden see a 10% drop in my mileage with no change in driving habits. I then read of the new mandate about 30 days after it went into effect. I started filling up on the Kansas side of the metro area where there was no ethanol mandate. My mileage has since returned to what it was before. Needless to say I am not an E10 fan. If ones mileage drops 10% with the introduction of 10% ethanol, then I is no benefit other than to drive grain prices up.