Which Engine Should I Choose for my Zero Turn Mower?

what is the best engine for my mower

We get asked all the time which engine is best. Or just as often for confirmation that a brand is the best. (eg. “Brand X” is the best right?)

If I were to ask you, “is Chevrolet the best choice?” it would be hard to answer without knowing which Chevrolet we are talking about. There is a world of difference between a Corvette and a Chevette, yet they are both Chevrolet.

It’s much the same in the engine world. When we are talking about the very best each company has to offer, they are all solid commercial engines that are extremely unlikely to disappoint. These top model engines include:

➤ Briggs & Stratton Vanguard➤ Kawasaki FX➤ KOHLER Command Pro➤ TORO ZX‍If all these companies can make a great engine then why does Kawasaki’s reputation seem to be so favorable and Briggs & Stratton’s reputation poor?

The difference is where they draw the line at the bottom of price and quality. Kawasaki’s bottom is their FR model which is a high end residential engine. Briggs & Stratton on the other hand will build an engine for almost any budget and it’s the cheapest lowest quality models that they tend to sell in the greatest volume and end up hurting their reputation.

Because we often have customers walk in the door and say literally, "don't show me anything with a Briggs engine" we are hesitant to carry Briggs powered Z's unless it is their very best, the Briggs & Stratton Vanguard. Most of the mowers we stock are powered by a Vanguard, Kawasaki, KOHLER, or TORO engine.


The FX series is their best and also the model you will see the most of in the Toro line. The FT & FS series are also commercial, just not their very best. The FR is their high end residential engine which is basically a cheapened version of the FS, and still a very solid engine.


The Command series is their best and many of the Command models have hydraulic lifters (no valve adjustments needed) and closed loop fuel injection (+/- 25% fuel savings). Under the Command is the ZT (Confidant) which is also commercial just not their very best. Then the 7000 PRO mid-grade engine & 7000 consumer engine which has proven to be a reliable consumer engine and shares many of the same core components found in the ZT. Below that is the Kohler Courage which has a poor reputation mostly due to the single cylinder versions, many of which had problems years ago.


Most people don’t think of TORO as an engine company. But in fact they were founded for the sole purpose of building engines and later got into the mower business. Along the way they’ve manufactured many types of equipment even including cannons and maritime mechanical parts for World Wars I & II. They have quite a few small engines for Walk Power Mowers & Snow Blowers but just two core designs for Zero Turn Mowers. The TORO SX is a 16HP consumer engine that has proven to be reliable after several years on the market.

In 2015 TORO released the ZX engine which has become the most widely used engine in the Toro Z lineup. B T South has sold over 1400 pieces of equipment powered by this commercial engine and its outstanding  performance has pushed it into the same league with other top tier engines. There are three versions of the ZX, a 22.5HP version, a 24.5HP version, and a 24.5HP with a canister air filtration system. All three are the same core engine but have different carburetors and air filter components. Read more about the TORO ZX Engine’s features at this link.

The biggest advantage the TORO V-Twin has over other top tier engines is that TORO can have it produced less expensively than buying similar quality engines from Kohler and Kawasaki which frees up dollars to offer a lower mower price or to invest that savings in making the mower better in other areas like the frame, deck, spindles and tires. Part of the manufacturer's cost of an engine is the cost of standing behind the warranty. That cost is clearly very small for TORO as we see them continuing to offer longer warranties than competing engines of up to 5 years.

We often get asked if the TORO V-Twin is a re-branded Kohler, Kawasaki or Brigggs. It is not. Toro developed and tested this engine's design for their own use. TORO has it produced by an industrial machining company to meet their exact design and standards. TORO calls it the TORO V-Twin. Exmark calls it the Exmark V-Twin and you might see it used by some of TORO's other brands as well.

What about HONDA?

Honda is a major player in the single cylinder engine market for products such as walk behind mowers and other small power equipment. But for whatever reason, their larger twin cylinder engines, which are a size more suitable for riding products, have just never caught on and are not prevalent in our industry.

Engine Life

First, realize that a big part of an engine’s life is maintenance. In particular changing the oil, changing the air filter, and cleaning debris from the engine as needed to allow it to properly cool. Also very important is proper fuel management and using the correct engine oil, as most automotive oils manufactured after 2009 do not meet the specifications for air cooled engines resulting in higher operating temperatures and reduced engine life. Commercial engines are of course designed to last for more hours of use, but even good consumer engines can last for decades when maintained well and not used excessively.

Likelihood of manufacturing or design defect

Every manufacturer has an occasional problematic model or defective unit.

Kohler for example had issues with its early models of the Courage engine, the single cylinder model in particular.

Kawasaki had inexplicable problems with some of the early models of the water cooled FD series.

Toro, while I don’t recall a problematic engine from them, their 300 Series Z-Master was a problematic mower. The point being, even the best of the best companies are not perfect.

All three of these manufacturers make solid products that are very reliable for the overwhelming majority of their customers.

At B T South we are very selective about the products and manufacturers we choose to carry because in the event there is a problem, the customer comes to us for a solution. We are not like the big box store where they just hand you an 800 # to get rid of you. It is a rare and unusual situation that we would have to send someone out the door for a solution somewhere else. Our business model is to sell quality products that work and to be able to provide any needed parts, service and warranty in our store.

What happens when there is a manufacturing defect?

In the event of an engine defect, how will the manufacturer stand behind the product? When it comes to warranties you can count on most manufacturers to step up and take care of the problem when there is a clear “black and white” defect.

Unfortunately there is a lot of potential for gray area in warranty coverage. One of the things I admire about Toro and Kohler is their traditional American customer service attitude. They understand the customer paid for their quality product and even in the "gray areas" are typically willing to step up to get things right in situations where other manufacturers would not.

When they have a known defect they admit it, and in such case often help the customer even beyond the expiration of the warranty. Of course if there is evidence a failure was caused by abuse or lack of maintenance then we need not expect the manufacturer to be responsible.

Many of the other manufacturers of engines and of lawn mowers don’t tend to be so generous. Japanese companies in particular tend to be resistant to admitting problems and hence taking responsibility for failures.

Years ago when when Honda lengthened their warranty by an additional year, there was a spoof document sent around among dealers as a practical joke that said “Good News! your Honda warranty claims will now be denied for an additional year” That of course is not true.

Honda certainly does approve some warranty claims, but there is a grain of truth in most jokes including this one. And the grain of truth is that with some companies it feels like the customer is guilty until proven innocent and that we have to fight tooth and nail to get the manufacturer to step up.

Is the Engine the most important part of selecting a good Zero Turn?

While the engine is a very important part of a lawnmower, it takes more than just a good engine to make a good lawnmower. There are other factors like:

  • Quality hydraulic components for smooth operation and long life.
  • A rigid mowing deck built heavy enough to stand years of rust and impacts.
  • A mower frame strong enough not to break or warp.

And there are qualities that can’t easily be measured by numbers, like:

  • Weight distribution balanced to optimize traction
  • Maneuverability and hillside stability.
  • Deck aerodynamics to maximize cut quality and clean cutting speed.
  • Expensive quality components alone don’t assure performance.

Some manufacturers try to employ one or two quality components or brand names that are popular on shopper’s check lists and then skimp on quality in other areas compromising overall performance and longevity.

In general, a better mower can be built with more money, but to get the most bang for your buck means to balance the expensive components to meet a budget and combine those components with sophisticated engineering to maximize performance.

The reason we’ve chosen Toro as the core brand of our business even after being offered more than twenty-two competing brands is because Toro brings the most bang for the buck in a wide array of different budget levels.

The TORO ZX engine is a good example of how TORO has been able to bring more value. This ZX engine brings the commercial feature set of a top tier engine without the top tier price.

Maximizing performance per dollar along with industry leading support after the sale and long term parts availability is how Toro has become the most trusted brand in the industry. View the current Toro Z lineup at this link.

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