Top 7 Aftermarket MPG-Boosting Prius Accessories

The annual SEMA show, the ultimate pimp-your-ride Las Vegas extravaganza, wrapped up last week. The crazy body mods, garish oversized wheels, onboard big screen TVs, and high-horsepower antics got us thinking about what aftermarket products make sense for our mild-mannered hybrids.

As you might expect, boosting mileage is the name of the game. But looking a bit cooler, and easier access to your iPod, are not out of the question. Check out our seven nominees for the top hybrid accessories, and let us know if you have other suggestions.

More details about each product, and links to the Hybrid Cars store—courtesy of our shameless promotion department.

1EV Button


EV Mode button

The Prius “Electric-Only Mode” option package is available for second generation Priuses, from 2004 to 2009. (The newer model comes standards with the EV button.)

This replica of the OEM option—which was a de facto feature of Priuses in Japan but was disabled in North America—can be installed in minutes. Activating the EV mode via the button will put older models into gas-free EV mode for small stretches. The overall boost in mileage is modest, but it gives you a sweet taste of things to come from plug-in hybrids. (Acceleration past 34 mph kicks you out of EV mode.)


2Kiwi – Diagnostics Game


Kiwi MPG Game

If information is power, then the Kiwi is omnipotent for a hybrid. The Kiwi device plugs right into your existing on board diagnostic port near your steering column in a matter of seconds. Once installed, the Kiwi works like a game—rewarding you for sensible driving and observing the speed limit, and penalizing you (and your mileage score) for jackrabbit starts, excessive speed, and heavy braking. Think of it as a more useful and engaging screen than the one supplied by Toyota. By some estimations, playing the Kiwi mpg game can save you hundreds of dollars at the pumps. It’s compatible with all vehicles, not just hybrids, from 1996 and up. PLX, the company behind Kiwi, frequently wins top innovation awards at SEMA.


3Modellista Aero Tourer Prius Kit


Modellista Aero Tourer Prius Kit

Tired of your Prius being called an ultra-nerdy appliance on wheels? Take matters into your own hands with a new streamlined look, courtesy of Modellista, Toyota’s in-house tuning arm. Imported directly from Japan, the Modellista kit includes front bumper, front grill and emblem—and is manufactured with a combination of fiberglass, plastic, and flex resins. Actually, there are three separate body kits available that offer varying levels of flair: Modellista Versions 1 and 2 and an Aero Tourer Kit. The added bonus of the Aero Tourer Kit is better aerodynamics.


4Prius Chassis Stiffener Kit


Prius Chassis Stiffener Kit

The Prius chassis stiffener provides a rigid framework under the car to eliminate chassis flex, ensuring correct suspension geometry. It bolts directly to the subframe to further stiffen the unibody. You’ll notice a more stable and solid feel, especially when turning around corners—and a modest nudge in mpg, according to the manufacturer.

This is a bolt-on item manufactured to OEM standards. Four stainless steel bolts and washers are supplied. It only takes a few minutes to install the plate. Easy, detailed instructions are included.





Prius drivers receive a lot of critical information about energy use and consumption from the navigation/energy screen. But it can be drag to read the screen when the sun is blasting down. Install the NavCap and stop squinting. Made of textured and molded 1/8-inch ABS plastic. The under side is lined with a soft material and attaches easily with a heat resistant Velcro material. Made for Priuses, 2004 – 2009.


6Neo Prolink Toyota iPod Adapter


iPod Adapter

This item doesn’t save gas, but it could save your life. Fiddling with your iPod while driving down the road is a hazard. You shouldn’t be messing with your tunes at all, but with this iPod adapter you can control your playlists directly from your dashboard touchscreen or, when in “direct mode,” from the track buttons on your radio and steering wheel controls. In “playlist mode,” you will have direct access to your top 99 playlists. The Neo ProLink is compatible with all iPods with a dock connector on the bottom. The device works with Prius (2004 – 2009), Highlander Hybrid (2005 – 2009), Camry Hybrid (2007 – 2009), as well as Scion xB and xA (2008 – 2009).


7Thule Prius Bike Rack


Thule Prius Bike Rack

The best way to save fuel is not to use it at all. That means getting out of your Prius and jumping on your bike. It’s never been easier to bring your bike along, than with the Thule rack. Designed for the Toyota Prius (2004 – 2010), the Thule has a two-bicycle carrying capacity, and provides a perfect combination of security and convenience—featuring quick-release levers for rapid, rear vehicle access and folding arms for storage. This item, which is compatible with Thule’s STL2 hitch lock, and 538 Cable, weighs 33.5 pounds. Limited lifetime warranty.


And with the Toyota floor mat recall in full swing, it’s time to upgrade:

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  • Anonymous

    i fail to see how Prius Chassis Stiffener Kit in theory can actually boost fuel economy. It gives you no weight advantage nor contribute to the aerodynamics of the car. Only advantage I can see is handling which should have no affect on mpg.

  • AP

    Anonynomous, you are spot on. That is one bogus claim!

  • Mikey95112

    Intuitively, chasis stiffening does not sound like mileage performance improvement. But consider this, handling improvements do indeed improve cornering and traction. Thus, while seemingly insignificant, being able to improve by putting more horsepower applied to the road, there is “some” mileage gains. Ask any aftermarket performance shop or driver and they will agree. Their goal may be only to improve 1/4 mile performance or 0 to 60 times, but it can up add up when looking at a full tank of gas. Consider this, even a fraction of a mile improvement per gallon of gas is exactly that. Multiply that by 10 gal per tankful of gallons of gas per year. Don’t expect a miracle when you already own a very efficient Prius. In science, we have the law of diminishing returns where it gets harder and harder to “improve” each step of the way. But knowing you have a Prius, you’re way ahead of all those gas guzzlers!

  • Anonymous

    I’d disagree… if one is doing that much cornering, it is more likely the gain is due to slower travel speeds rather than improved turning performance.

  • AP

    “Ask any aftermarket performance shop or driver and they will agree.”

    Aftermarket performance shops are often wrong, and they have a vested interest in selling you whatever they have-effective or not.

    “In science, we have the law of diminishing returns where it gets harder and harder to “improve” each step of the way.”

    That’s true, and that’s why it is harder and harder to improve fuel economy economically by adding electric motors, batteries, etc., to make a hybrid. The added mass and cost of the hardware puts you in a hole that you have to make up for.

    But this chassis stiffener is one step beyond that. Even if the Prius is a basket case for body structure, the miniscule amount of energy that would go into body flex would never register 0.001 MPG difference.

    You are dragging more mass around, however, so it will REDUCE your mileage on that account. The brace probably makes the car feel better-they should just leave it at that.

  • hybridkansas

    Folks, the chassis stiffener will indeed have a miniscule improvement in mileage. It’s really quite simple: proper alignment (steering and suspension geometry) allow a vehicle to track easier, no matter if cornering or driving straight. The device is machined from light billet aluminum so would have a trivial effect on weight.

  • Anonymous

    “proper alignment (steering and suspension geometry) allow a vehicle to track easier, …”

    Do you know what you are saying here? By saying car would be properly aligned, you are basically saying the car is not properly aligned to begin with. So now the plate helps the suspension too? COME ON! What are you going to tell me next? The plate is going to help the car float in the air?

    You can explain it anyway you want to, the science don’t make any sense in multiple angles. Even if the plate weights an ounce, it’s NOT CONTRIBUTING to the efficiency side to make it happen. Drop the snake oil claim and I just might believe the suppose handling benefits.

  • younona

    I suggest you the transfagarasan = route. See why on this video – Top Gear in Romania –

  • Ute Bull Bars

    These are some very cool tools that has been listed on here. Some of them sounds alright such as the nav cap and ipod adapter, but how assured can we be that the rest of the gadgets would equally work well. I have to say I agree with ‘Anonymous’ and ‘AP’ on this. Still I would like to give kudos to the author of this post. Quite a creative one!

  • tapra1

    The Kiwi device plugs right into your existing on board diagnostic port near your steering column in a matter of seconds. Technology Review

  • lojmuscle

    Chassis stiffner is a waste of $$$$$$$$. Google the Voranado a device that supposedyly causes a “tornado-like” air flow into a car’s intake. Bunk! all it does is reduce air-flow, yet company has made lots of $$$ selling them!!! Folks- its a small piece of aluminium!!! It does not improve cornering-dimensions too small ,and it will not improve MPG! I reccomend K&N air filter. I put one on my 2009 Prius and I noticed the difference right away- BTW K&N offers money back guarantee!!!

  • Frank Smith

    The K&N filter does not work. Too many product testing groups have said that it does not work on any hybrids. You say that the stiffner doesn’t work, but you got suckered into buying K&N.

    I’ve used K&N in all types of vehicles and it only works really good on cars with a carburetor. Plus, I’m a former mechanic and can tell you for sure that they don’t work as advertised.