The Curious Case of the 600,000 mile Hybrid Electric Taxi.

March 25, 2024
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I’ve been waiting for something like this to happen, because…I knew something like this was eventually going to happen. It’s a second-gen 2007 Toyota Prius, and it clocked a verified ONE MILLION kilometers on the original battery pack and engine (621,000+ miles).

First, I’m going to list some info about what a Prius is, and then I’ll list a few hybrids that made it to very high miles, so we can see if there’s any pattern that we can learn from.

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Toyota Prius, Gen-1 (1997-2003)

In 1995, Toyota premiered their prototype hybrid Prius at the Tokyo motor show, and the very strong response encouraged them to go into full production. This was a full eight years before Tesla showed that a pure electric EV could perform well and still have decent range, in 2003.

Although today, Toyota and many other car companies have begun producing full electric EV’s, Toyota also remains committed to keeping several hybrid models in their line-up. One of their concerns from the beginning is the availability of public charging stations. It can be a problem for those times when you want to drive farther than just a short hop to work and back, or just running errands near your home.

Also, North America now has quite a few public charging stations, but that leaves many countries that don’t…

It’s true that as of 2024, the public charging network has expanded a tremendous amount, and due to the huge number of Tesla charging stations (and also how good of a design they are), several of the major car companies have wisely adopted the “NACS” Tesla plug standard. To see our article on that, click here. Now, since so many car companies have signed on to use the same type of plug, those stations will increase in number even more.

That being said, I have one of those charging stations near me. Sometimes, all the slots are completely full of EV’s, and some even have another car waiting for one to finish charging. As more public charging stations get built, more people will buy EV’s, so…car buyers still can’t be certain on a long drive that they will be able to find a place to charge, and they will have to wait to even get started. To be fair, most EV owners have a charging station in their garage, but rental-dwellers have expressed difficulties in persuading the building-owner to allow a charger to be installed.

After three years, Toyota had collected enough driver data that they were able to make upgrades to improve the design for the Gen-2. The Prius design is not a plug-in hybrid, its a parallel hybrid where both the engine or motor can directly power the driveline to the wheels.

If you are comparing it to a conventional gasoline engine, the worst fuel mileage and worst emissions are from the low-speed acceleration when a traffic light turns green. This situation is where an electric motor shines. The size of a car engine must normally be sized to handle the heaviest loads it will see, however…if you add an electric motor to handle all the acceleration loads, the engine can be smaller, and even the battery that supplies the motor can be fairly small. This is important, because the battery is one of the heaviest and most expensive parts of a pure EV, and the Prius format was able to be sold to the public in 1997 for only $16,500.

A 2004-2008 Gen-2 Prius

The biggest complaint against the Prius was that a parallel hybrid has the engine directly driving the drivetrain when on long trips, so it’s no better than a gasoline car. It just has an electric boost at lower speeds. In this configuration, the 201-Volt traction battery is very small, in order to keep the price and weight low.

This configuration results in the city fuel-consumption being much better than the highway fuel consumption. City taxi’s are regularly reporting an economy near 50-MPG around town, with highway driving providing around 32-MPG. The highway mileage is not bad at all, but it may not be “good enough” to make the price premium worth it. As an example, the 2024 Ford Escape (gasoline-only, avg 30-MPG) is roughly an MSRP of $30K, and the plug-in hybrid version is $40K…IF you can find one that hasn’t been marked up more than the MSRP’s $10K premium.

2004-2008 2nd gen

There were quite a few small differences between the 1997 first-gen Prius and the second-gen (internal code-name “XW20”). The second-Gen was changed to a hatch-back with other interior convertible-features and compromises to increase cargo capacity. For instance, the rear hatch is a generous 43 inches at its widest part, along with being 23 inches tall.

The depth of the rear cargo area (front to rear) is 45 inches (shown on the left side of the pic above), and…with the rear seats folded down, this is increased to 70 inches deep (6 feet, 10 inches). In the pic above, the front passenger seat is also folded down, for an impressive 126-inches, which can fit several surfboards that are 10-feet long, while still allowing two seats on the left side of the Prius for a driver and one passenger.

Because of the Prius’ ability to allow two adults that are six-feet tall to sleep in the back, the 2nd-gen Prius has become popular for weekend campers.

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How do they last so long?

This is the heart of this article. If a gasoline engine with its automatic transmission lasts to 200K miles, it is considered exceptional, and having the gas engine break down at 150K miles is not surprising these days. The hybrid examples provided below are all over 300K miles, and that whole time they all got roughly 50-MPG in city driving.

As far as emissions go, the Prius is rated as an “Advanced Technology, Partial Zero Emission Vehicle” (AT-PZEV). So, even with the engine running only half the time that the vehicle is driving (in city driving), it is burning as clean as possible when it did run.

The second-gen Prius uses a nominal 201V battery pack made from 168 cells using the Nickel-Metal-Hydride chemistry (NiMH). The size of the pack is a VERY TINY 6.5-Ah. The controller keeps the battery State-Of-Charge (SOC) between 40% and 80%, by turning the engine on and off as needed.

The pack has active fan-cooling, and this is important. In the past, Toyota has designed many sophisticated liquid cooling systems, so their conscious choice of an air-cooled pack was made to save on weight and cost.

In order to have a battery pack last a long time, you have to keep it from getting hot. This was a major issue for the Nissan Leaf EV, which only used passive cooling from the cabin, with hot climates being expected to push drivers into using the air conditioning. However, the thicker portions of the Leaf battery pack still suffered from too much heat during hot summers, with a great deal of heat rising off the ground to warm the bottom of the pack. Here is a short scientific commentary from Phoenix, Arizona.

The Nissan Leaf EV is the best-selling EV in the world so far, and a big part of that is the low price. Even though Nissan had to pay some warranty claims due to the battery pack degrading its range too soon, they apparently decided that the cost of paying-off a few claims was worth keeping the lower price. So far, Leaf owners in very cold climates have never suffered any summer degradation.

However, Toyota opted to use a direct fan-cooling system that is built into the Prius battery pack case. Also, because of the small size of the pack, their fan-cooling is adequate, and at the very least it allowed all the cells to warm and cool evenly. For a comparison, the Nissan Leaf pack has an odd shape, with thin sections and thicker sections, and the centers of the thickest sections were degrading from heat the soonest.

A Toyota Prius hybrid battery pack, which owners can easily change-out themselves, if needed.

Tesla uses a sophisticated liquid cooling and heating system for their battery pack, but…of course they are also more expensive. Now, let’s move on to our examples…

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336K and 349K

Jesse Rudavsky’s 2nd-gen Prius had 336,100 on the odometer when it was damaged in a road accident, so he went out and bought his THIRD Prius for his ride-sharing job…

“…I used the car every day as a full time Uber and Lyft driver…I really want an electric car but unfortunately my wife and I live in an apartment and have no place to plug in other than a questionable two-story level-1 cord. If I had a place to plug in every night and had the money, I would buy a used Tesla model 3…

…In order to hit 300k or better it’s pretty simple. I change the oil every 5K miles or so, using the required 0w20 full synthetic oil. I also change the planetary gearset fluid out every 100K or so. All batteries have self-discharge to a certain extent depending on the chemistry, and I don’t recommend letting the car sit for weeks…”

Jesse’s previous car was gen-one 2002 Prius that reached 349,531 miles on its odometer.

His story can be found by clicking here.

A 2002 Gen-1 Prius when it was owned by Jesse Rudavsky. The first Prius was only available as a sedan.

At that time, Jesse was the president of the “New England Electric Auto Association” (NEEAA), so I will forgive him for not owning an electric bicycle. He is also a “Storm Chaser” which is one of the reasons he logs so many miles every year. He now lives in Oklahoma with his lovely wife, Brittany.

Below is a link to a 12-minute tear-down video of a Prius engine at approximately 300K miles. The mechanic points out the clues that show the engine did NOT get its oil changed often enough, which is why it failed. To me, THIS is also amazing. You can abuse the most basic maintenance on this engine, and it still lasted over 300K miles. Of course, the engine may have only been running for half that, maybe 150K?

A Toyota Prius 1.5L 1NZ-FXE engine

To see the 12-minute Prius engine teardown, click here.

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400K

Ford confirmed that the 400,000-mile hybrid drivetrain contained the original NiMH battery that is mated to this 2.5-liter 4-cylinder engine, with a continuously variable transmission. It is cab #7G76

The MSRP on this 2012 Ford Escape Hybrid Taxi, when painted in School Bus Yellow, was $32,940 after delivery.

That story can be found by clicking here.

A second article on this hybrid can be found by clicking here.

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442K

Here’s a story about a 2009 Toyota Prius owner from Florida, who recently traded in his old Prius for a new Prius V. His occupation, as a medical supply courier, allowed him to travel an average of 3,100 miles per week. Here are some details about that particular car:

“I used Mobil-1 0W30 for the first 100,000 miles. Used Mobil-1 5W30 High Mileage for at least 200,000 miles. I went to Royal Purple oil, which I liked because it slowed the oil consumption. I used a Purolator 14477 filter. Oil Change intervals were 10,000 miles, in all highway driving. Car started burning oil at 390,000 miles (one quart/1900 miles, in a 3.9 quart oil sump) at which point, Royal Purple oil was used.

This car still had the original brake pads, due to using max regen, and the car averaged 48-mpg over 60 mph”

The story is located in the middle of a 60-page forum discussion on Prius’s that have gone over 300K miles, find it by clicking here.

“…Update 442,096 miles. Slight coolant burn. Nothing coming from tail pipe [*smoke]. Had about 3 slight misfires over 2 week period. Still going strong…”

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478K

“…2010 Ford Escape here with 478k miles, 2.5L Hybrid AWD limited.

  • Oil changes every 10K (Mostly all highway)
  • Transmission fluid change every 30K miles
  • New Transmission every 100K Miles
  • New brakes only twice replaced
  • MPG is 27 Combined (And I drive like a crazy person)
  • All fluids changed every 100k miles
  • Replaced A/C at 150K miles and at 300K (Very annoying)
  • Hybrid battery no codes but has about half life left
  • No rust so far (Live in PA which still amazes me)
  • Yes, I do baby this small truck/Suv
  • Doesn’t need it right now but will be replacing spark plugs again, last time was at 400k, try to every 100-150kish
  • Starter went out only once at 88k…”

This story can be found by clicking here.

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493K

“…While riding taxi’s in New York City, I saw several Ford Escape Hybrid taxi’s and I ran their license plates through Carfax, and each time the numbers came up with astronomical figures. The highest-mileage Escape Hybrid that I found was a 2009 model that had racked up 493,936 miles since its original purchase from Manhattan Ford on May 19, 2009. For those of you playing at home, that’s 214.3 miles per day. Every day. For nearly six and a half years. Their power delivery is good, with plenty of low-end torque for passing maneuvers…”

Random Pic of Ford Escape hybrid taxis in NYC

That story can be found by clicking here.

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500K

“…A white base-model 2008 Ford Escape Hybrid has just crossed 500,000 miles. Bayer Protective Services, a private security-patrol company in Sacramento, California, owns the hybrid Escape, known as Car 804. Best of all, Bayer says, the half-million-mile hybrid Escape continues to deliver the consistent gas mileage that made it an attractive buy in the first place, 35 mpg…”

A 2008 Ford Escape Hybrid

That story can be found by clicking here.

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550K

This was an important example for me to find. I had started thinking that maybe the long-lasting battery packs were the NiMH batteries, but this one is a 2017 model with a lithium pack.

It’s a 2017 Toyota Prius “Gen-5” with 550,000 miles, which was used mostly as an Uber. This model is powered by a 1.8L 4-cylinder engine which is assisted by two electric motors. Combined output is 134 horsepower.

The battery is made from 56 Lithium cells with a nominal voltage of 3.6V X 56 = 201V, and when fully charged to 4.1V per cell, it rests at 230V DC.

This story can be found by clicking here.

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560K

“…I’ve found one particular taxi that stands above all the others: It’s a 2009 Escape Hybrid, with 560,415 miles. It’s taxi number 8F63…”

That story can be found by clicking here.

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584K

This auto repair shop in Denver, Colorado came across a customer’s 2008 Toyota Prius that had 584,613 miles on the odometer. Here is a 40-minute video on swapping a battery by yourself to save some money. I’m parking this link here because this hybrid did have its pack replaced.

A Prius battery pack that has been refurbished with new cells. Notice the air-fan on the right, and the air-spaces between the cells.

Not surprisingly, this particular Prius was still rocking its original engine and transmission. The shop owner did admit that they’ve already swapped the battery pack on this Prius. Typically, Prius owners can eke out over 200,000 miles pretty reliably before a battery swap is warranted.

You can find this story by clicking here.

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621K

Now, for the star of this article. A taxi company called ”EcoTaxi” is located in Vienna (Austria), and has a fleet of about 200 hybrid Toyotas. The driver is Manfred Dvorak. There are quite a few articles about this particular Prius taxi, because in Austria, it logged over one-million kilometers, which is 621,000+ miles.

I want to point out that Austria is the same latitude as Canada, with mild summers and cold winters. It is no longer being used as a taxi, and is now used as a roadside assistance vehicle. The original battery lasted 700km (435K miles), and it was replaced once.

In 2017, we wrote how Tesla had figured out how to make lithium batteries last longer, and to see that article, click here.

In 2019 we wrote about developments that would result in lithium batteries that would last 20 years of full-time driving in an EV, and to see that article, click here.

And here is a 2021 sales advertisement for five used hybrids with ultra-high miles, and to see that, click here.

I suspect that the on/off nature of the hybrid system when using the battery is a key factor in allowing the battery to avoid getting hot. The small battery supplies high amps for accelerating, and then the engine comes on to power the vehicle when just maintaining speed.

I’ve been keyed-in to watching hybrid vehicle developments for a long time, because of their high-amp cells. Electric cars with a large battery pack are able to get high system amps from cells that are designed for long range (high capacity), but that’s only because of how large the pack is… However, if you break down the pack and reconfigure the cells into a small pack for a DIY conversion where you still draw high amps from it, the individual cells will get hot.

That’s why I have recommended hybrid vehicle cells for hot rod E-motorcycle conversions and hot rod ebikes. Not only will a small pack provide high-amps, but even if you don’t need high amps, the fact that these cells can provide that means that under normal use, the pack will run cool…for a very long time.

Hybrid cars sometimes get in wrecks, and as a result, there is a thriving market in used packs and cells. For a link to just one of those suppliers, click here.

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Written by Ron/spinningmagnets, March 2024

Grew up in Los Angeles California, US Navy submarine mechanic from 1977-81/SanDiego. Hydraulic mechanic in the 1980's/Los Angeles. Heavy equipment operator in the 1990's/traveled to various locations. Dump truck driver in the 2000's/SW Utah. Currently a water plant operator since 2010/NW Kansas

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