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How To Potentially Fix Oil Consumption On Your Toyota Prius

The Toyota Prius is more than a car. I believe that when it was engineered, the Japanese army gave it some DNA from a tank. Even though this tank-esque car is unbelievably reliable, it still has areas that can prove to be pesky as the miles climb up and the maintenance gets avoided. Oil consumption is a known issue but why it occurs and how to avoid it are things that are fully understood, until today.

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Ever since I became a Toyota Prius owner, I have found that this is a whole new culture of people. Prius owners I find are genuinely involved and concerned about their cars, they love them and want to own them, forever. Toyota knew that they needed to build something that would leave a lasting mark on history and change the way we look at transportation forever. Prius the "before" car has been one for the books for sure. It also is not perfect, and with known issues such as oil consumption this has left some owners wondering if this is the end.

My answer answer from a technicians stand point is no, it is not over. Most owners just need to know a little more about their car in order to avoid some of these issues. As the Prius continues to make history and prove itself in the heat of battle. It also shows us that blasted achilles heel. I want to help my readers by learning what can cause oil consumption issues on our beloved rides and what we can do to prevent it, and potentially fix it.

What Is And Causes Oil Consumption

Understanding anything requires us to know what it is. Oil consumption in our Toyota Prius is when the gasoline engine actually uses the engine oil in large quantities between changes. For example, under normal operating conditions, your engine could consume up to 1/2 quart of oil over 5,000 miles. My 2007 however is using much more than that. Up to a quart every 500 miles, totally unacceptable.

Most vehicles, including Prius should not even consume this amount. There are several things that contribute to this. One being how we treat our engine oil. Due to the nature of Prius we start and stop the engine quite frequently. This action heat cycles the engine oil and causes the additives in the oil to wear out faster. When these additives are depleted the oil breaks down and leaves carbon, sludge and other deposits. This junk then gets caught up in oil passages and embeds itself on piston ring lands.

The piston rings are there to prevent oil from entering the combustion chamber while also providing the compression needed to run the engine. When deposits get caught in the ring lands (where the piston rings sit on the pistons) this does not allow the rings to seat properly inside the combustion chamber. If the rings are not sealing properly this means that oil can creep past and get into the combustion chamber and be burned. Also the PCV valve can be an issue as well, and in yesterday's article I covered that.

I want to fully disclose right here that is may not work for every instance. Sometimes if you have neglected your engine too much it has mechanical damage that would have to be repaired by a rebuild or replacement of the engine. However, if you want to try a less expensive option, this may work and here is why.

Oil companies want to brag about how great their lubricants serve and protect your engine. Most do not know what oil to choose or whether they should do conventional or synthetic. I have a great article that can help you determine what oil you need if you are wondering. This also means that they do loads of research how to keep your engine clean and running well.

While oil companies can make great products but, they cannot keep Prius owners from going too long in between oil changes. For this reason some, such as BG have come up with products that can help clean out leftover deposits.
Carbon is one of those deposits that is a hard and does not just burn off without a fight. A carbon softener is required to break down the hard material and allow it to burn off. As we do this, the piston rings can reseat and oil can once again be blocked, restoring engine integrity.

Products/Process That Are Ok For Prius

Choosing a good carbon softener can be about as easy as finding engine oil, if you know what you are looking for. I will cover these option more in depth later. For now 3 products I recommend are BG 44k, Motorvac, and Seafoam. Each of these can soften the carbon and allow it to burn out through normal combustion. Each one of these will work for the Toyota Prius.

I have found, for me, the best way to utilize these products is to directly use them at the source. I did this by pulling the spark plugs and putting the chemical directly into the cylinders and letting it soak for a few hours. I used a borescope and watched the results.

After about 30 minutes I was able to scope each cylinder and see which one had the worst problem. The chemical will soak into the carbon and you should see it "dry up" meaning that it has softened the carbon to allow it to burn off during normal engine use.


In theory, all of this should work and in speaking with other technicians, they have had good results on Prius doing this method. BG also makes a hybrid kit that is specific to this issue and so far has been seeing great results. I will be using this product on my 2007 to try and see if it can fix the issue that I am facing as well. I will have more on this as events unfold and as I gather more data.

hope that you have enjoyed reading about new Prius Technology. Check out my other story 3 Top Tire Brands You Should Consider For Your Toyota Prius to find even more ways to make that fuel sipper go the extra mile.

See you in the next story where I am discussing why the Toyota Prius AWD-e is the best one yet.

Also Watch New tech means more MPG from your Toyota Prius and Click to Subscribe to Torque News Youtube Channel for Daily Toyota Prius and Automotive News.

Peter Neilson is an automotive consultant specializing in electric cars and hybrid battery technologies. He is an automotive technology instructor at Columbia Basin College. He holds a Bachelor of Science in Automotive Service Technology from Weber State University. Peter can be reached on Linkedin and at Certified Consulting

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jg (not verified)    July 27, 2019 - 3:05PM

I can attest to the "tank" metaphor, I had a 1st generation Prius for just over 10 years and it had the original brake pads with over 300,000 miles on it (slow stops maximizing the regenerative braking)! Had a few things taken care of in warranty, but never had any major issues. I only traded it in because it quit holding 65 mph going up a hill on my drive home and the dealer wanted $900 to replace a component so their troubleshooting computer would even talk to the car computer -- then they could tell me what was wrong with it. Obviously the batteries were on the downward slide and if I had known about the single cell fixes/repairs that have recently come to light I probably would have kept it for another 10 years.

Kim (not verified)    August 20, 2019 - 12:31PM

I own a 2011 Prius with a bit over 200K on it, all original. Last year it began to spit and hesitate when taking off and later repeating the spit and hesitation at higher speeds, thought I was doomed. Two dealers said I needed a new intake manifold, pipe and intake cooler as the fins were clogged and it was documented that Prius was made with those parts too small so they offered modified parts at a total cost of $2000-$5000 for replacement. Toyota sent out a service letter about this problem, not a recall. I watched videos of people replacing the parts themselves with some simply cleaning the parts. I have no place to do either so I bought some Seafoam and researched for the highest grade gasoline available. I started using a can of Seafoam with every tank of Shell super unleaded and over a 4 month period cleared up the spit and hesitation. Now I add a can every other fill up of Shell super and I always wait until my tank is down to 1/4 at least every time I put gas in. I wonder if I would benefit still yet from the BG treatment as my oil consumption is around 1/2 qt every 1000-1500 miles, more so in summer months. Might as well try, this little car has to take me 200,000 more miles!

Mike Belluomo (not verified)    August 22, 2019 - 4:00PM

In reply to by Kim (not verified)

I would absolutely say that using BG44K every 8K would be of great benefit beyond what you are doing. Seafoam is a very popular worldwide additive. However it consists almost entirely of isopropyl alcohol (fuel drier). It has no actual "deep cleaning" fuel detergents and relies solely on the chemical action of the "oxygen rich" alcohol to enhance fuel ignition and better fuel burn. In terms of actual deposit removing ability for cleaning injectors it's potency is zero. A superior cleaner will cost more, but will also deliver 1000X more actual cleaning of your Prius fuel system. After all, there is a reason Seafoam costs less than Ginger Beer.

Michael Carey (not verified)    November 20, 2019 - 5:48PM

Thanks for your thread. You have saved me a heap of money already with your POA93 information. I bought a electric water pump for the inverter off e-bay for US$30 and put it in easily. Problem solved. My 07 Prius did 408,000 km before this code registered and the only other thing I have done is brake pads round 300 km which is due to the type of driving I do, which is only highway driving for an hour each day traveling 110km/h all the way and only applying brakes at my destination. The 0420 code is showing and I am using more oil now, about 1 quart between changes, so I'll try the additives you mention to clean the carbon off the valve seats. I got lucky with this car I reckon. The body will disintegrate before the drive line does I reckon. Michael.

Fentisha Boswell (not verified)    December 2, 2019 - 11:54AM

Hi All! I LOVE LOVE LOVE my Prius, coming up on 192K and will drive it until my midlife crises and I can get the Prius Prime HAHA! Anyway, definitely burning major oil, so going to try these things (well I've asked my husband too) because of its burning alof of oil.

skip (not verified)    June 14, 2020 - 3:52AM

In reply to by Fentisha Boswell (not verified)

try marvel mystery oil in the gas and oil and see if this helps. I have a 2020 prime and I'm going and see if doing it from the start will stop it before id starts. the product does what it says it does. been around for ever.

Diane Bartok (not verified)    December 14, 2019 - 2:18PM

I was given a 2004 Prius Hybrid last year. It was a salvage vehicle, having 177,000 miles and came without a manual. This past week the red triangle appeared with the exclamation mark! Does that mean it's the hybrid battery and the car is not driveable? Or could it mean something else?

Eric M. (not verified)    January 18, 2020 - 1:43PM

In reply to by Diane Bartok (not verified)

That Red Triangle most commonly means that your prius is REALLY low on engine oil. I think the first time it popped up for my girlfriend she was a full 2 quarts low. I know it's been a month so I hope you found an answer elsewhere, but if you haven't here it is.

Charlee Thompson (not verified)    February 23, 2020 - 10:33PM

Prius 2013V is burning a lot of oil. After the last oil change did 1100 miles and needed a quart and 1/2. They say a rebuild is the only resolution or you could carry a case of oil in the trunk. Car has 130,000 miles, old 2005 Prius had over 250,000 and never had a problem. Toyota says they never heard of this issue...

Eric (not verified)    March 17, 2021 - 5:37PM

In reply to by Charlee Thompson (not verified)

While my local Toyota dealer was telling me that my engine had severe internal damage (it's gone another 60K miles since then), I was listening to a salesman tell a brand new Prius owner (2018 at the time) that it's perfectly normal for the car to consume a quart every 1k, and that's why you're supposed to change it every 3k.

My '07 has consumed about a halfquart every 1k for the last 150k miles, no idea if it did prior to that, i've only owned it that long.

Carey (not verified)    March 3, 2020 - 3:24PM

I'm uncomfortable pulling out my spark plugs, but would like to try these products to stem my oil from burning up. Are they all just additives that one puts in the fuel tank? Which product would you start with?

Larry McMurray (not verified)    September 26, 2020 - 8:52PM

Owner of 2010 Prius V, 130k miles it drank 3 quartz of engine oil... I tried the BG products ERP MOA & 44K
1100 miles since and oil level is unchanged! Please share this news, product works.

Bob (not verified)    December 13, 2020 - 1:35PM

This is potentially great news as my 2010 Prius has been burning oil like crazy and I suspect this could be the cause. Can someone post a link to the BG hybrid kit so I know exactly what to buy? Thanks.

Mustafa (not verified)    April 11, 2021 - 12:56PM

I`m using 2010 Prius Gen 3.My car mileage around 180k.I went to Miami from the Wisconsin last week (around 1750 mile,4000 mile total +trip in keywest miami ) i used 9 gallon fullsynthetic oil for my car.It`s too much i guess but some people says it`s normal,Idk which one is true but i used my car on the more than 75mph all the time while on the road.Sometimes i goes up 110 + mph.So in normally my oil is going down in 1000 mile,Is that normal ?

Adam (not verified)    November 29, 2021 - 1:25PM

I am definitely going to try this. I have a 2007 that uses about 1/2 quart every 1000 miles. How much chemical would you recommend mend putting into each cylinder once the spark plugs are removed?
Thanks for the article!

Popa Adrian (not verified)    February 9, 2022 - 2:10AM

Hi! I am driving an 2005 gen Prius. a couple of months ago I changed the oil and everything was perfect (ravenol vmp usvo 5w30) . now the problem is when i check the oil level.. it`s shows way above the max limit, around 15% more and the oil smells like petrol. I belive somehow the petrol is getting in the oil chamber.. how can I fix this?

Ali (not verified)    May 25, 2023 - 12:59PM

Hello All. I'm planning to buy 2023 Prius. Does hybrid system can cause oil consumption because engine goes ON/OFF all the time? Should I buy hybrid car? or better to stay with gas engine only? Please advise?