Has your hybrids fuel economy decreased since you first bought the car? Do you find yourself filling up at the fuel tank a lot more than you used to? Well it is a common symptom of a poorly performing hybrid and a common question we get asked about.
Often the main purpose for buying a hybrid is to spend less time at the fuel pump. Spending less on fuel without the restrictions of a full electric vehicle is a great compromise. However when your hybrid is suddenly spending more at the pump the reasons for buying one over a conventional ICE or full electric vehicle can seem like more of a concession.
The reasons for poor fuel economy in hybrids can be directly linked to the performance of the hybrid battery. We have seen from our own testing deteriorated hybrid batteries with low capacity or high degree of variation are consistently outperformed by reconditioned and new hybrid batteries. These days we offer new aftermarket hybrid battery builds in addition to reconditioned builds. Our new aftermarket builds offer new performance at a significant discount to the Toyota OEM equivalent. The fuel savings alone have made this option a preference for our clients in the passenger service industry.
In many cases the HEV battery is not at fault for poor fuel economy in fact the fault lies with an under-performing engine. Infrequent servicing, dark/dirty oil, blocked and dirty filters all contribute to more trips to the pump. However more specifically we are seeing issues arising from a blocked EGR system. Most commonly this issue is seen in the 2011+ Toyota Prius and Camry hybrids. The exhaust gas re-circulation (ERG) systems function is to recirculate exhaust gas back into the engine. The purpose of this system is to mix with incoming air and reduce heat in the engine cylinders. A cooler running engine means a more efficient engine in addition it recirculates unburnt fuel further increasing efficiency.
Blocked Intake
Dirty Egr Cooler
Blocked EGR Pipe
Clean EGR Cooler
In some cases the EGR system can become so blocked that it can cause misfiring of the engine at low speeds. These blockages are caused by the build-up of carbon from the exhaust air that is recirculating to the engine. These blockages can occur anywhere through this system from the EGR cooler, EGR valve, PTC and the air intake manifold itself. To resolve this issue we remove the EGR and air take system and do a full clean of it. Scrubbing all the inlets, valves and using an ultrasonic cleaner for the more difficult components. The result of this cleaning is a cooler more efficient engine. And in some cases the fuel economy of the vehicle can have an increase in excess of 5Km/L.
This sort of repair could cost thousands as many of these components are simply replaced because of the difficulty in cleaning them. In addition this sort of repair is only carried out once the vehicle is showing severe symptoms like engine shaking and misfiring. Often poor fuel economy is ignored as it is attributed to an expensive hybrid battery or simply because the vehicle is still running more efficiently than a conventional ICE vehicle.
If you find your vehicle is suffering from decreased fuel economy don’t put up with it. Get in touch and ask about our EGR system clean with our expert hybrid technicians.
Hi, How much is your charge for the above cleaning
We currently offer this for $650 including a standard service and replacing the EGR cooler.
Hi David!
One of your articles intrigued me so much that I have just spent over an hour reading through many of your other articles. In all my research on hybrids, I have never come across someone who has so thoroughly and expertly broken down the causes behind the symptoms we see in our malfunctioning hybrids while making it incredibly easy to understand. And that you would offer such valuable information and advice so freely. Thank you.
I was thinking I would be willing to drive across country to another state just so you could be our new mechanic but I figured out you live a whole ocean away!
I was hoping that since I can’t come to your shop that it would be okay for me to tell you a story and to ask you a couple questions on here?
After reading through some of your articles, I began to think that our little 2008 Prius, that barely made it home to die Sunday, may still have life left in her. Over a year ago, her gas mileage went from 48mpg down to 39mpg. We tried to theorize what might be going on but nothing else seemed wrong. One morning her engine began to rumble loudly at a stop sign and she felt like she was slightly shaking. We were actually on our way to the Toyota dealership to get her oil changed and I hoped it might resolve after that. Sadly, it never stopped. We took her back a few days later to get her symptoms diagnosed. They said that she was burning oil from a leak somewhere and her engine would die within the month and that we were better off getting a new car than paying $3,000 for an engine replacement on a car with 218,000 miles. We couldn’t even afford to think about either option that year and left there scared and hoping we could find a way to help her hold on for awhile longer. We began checking and adding oil everyday and she kept hanging on for us. One day we couldn’t get her dash info to turn on with the car. We had to drive without knowing it speed. We pulled over and for 20 minutes we tried everything we could think of to trigger that electrical connection like pushing her start button on and off over and over again and playing with the windows and brights. We don’t know hw but one of the times it finally came on. A few weeks later we couldn’t get her to turn off for two hrs. And then a few more weeks later and she began to push forward and loose power and pull back when she was going up hills in the cold. She continued to have weird electrical issues more often and her catalytic converter became clogged. The mechanics said there was nothing to be done. That she was dying and we were lucky c she hadn’t yet. But so far she had lasted a year and 5 months past when they said she could and we were hoping to help her feel better so she could have more despite her little issues. Last week she began to making a fluttering noise near the left side of the floor of the drives side when the engine was being especially taxed. We began driving extra slow so as to keep whatever was causing that from happening. It worked that day until we went home. We live I. The mountains of Colorado and have to drive up miles of hills to get home everyday after work. She began her flutter again going up one of those and this time it didn’t go away when we got to the flatter part of the road and could let off the gas. Energy seemed to barely get to the engine and we felt very lucky and surprised when she actually pulled up to the house. She hasn’t moved since.
After reading this particular article about blocked EGR systems and also the one about poor battery performance, I wondered if all the little problems she had in the beginning could have been due a blocked EGR system? We usually got her oil changed on a regular basis but always pushed it to the max time. The last time before all her big problems started, we actually were almost 1000 miles late because when we needed to do it our jobs wouldn’t give us any time off for almost two weeks to take her in. We commute over 80 in a day for work so it added up fast.
If the EGR system was blocked could the strain on the engine damage HEV battery cells in such a way To cause capacity deterioration that may go unnoticed by the mechanic but cause all the weird electrical problems we were having?
Do you think there is a possibility that if we do an EGR system clean and A reconditioning and rebalancing on her battery that she could run again?
Thank you so much for taking time to read this David!
I’m sorry it is so long. Please excuse me if this was not something I should have posted here.
Hi
A 2008 Prius does not have an EGR system. Shaking might be a dead engine coil should be a video link in the tips section. The 1500 engine is pretty solid I doubt any major issues. Fix up the HV battery and the engine missing and shell be good to go.
Hii David,
I bought 2010 prius and i have noticed that my car is giving fuel economy around 17.0 km/l. And my frd having the same car but that car is giving 20+. So is it the right fuel economy or something is wrong with this car? I have just done the service and they have changed oil and oil filter (mobil 5W30). If the oil is not synthetic then that could a problem?
Plz suggest what i have to do?
A basic service may not be enough we would have to see the vehicle.
What is the average fuel economy for 2011 toyota camry hybrid?