what is vtec? 27 april, 2000 by johnmichael patrick monty monteith

VTEC is first and foremost a marketing term used by Honda Motor Corporation of America.  VTEC is used to describe a variable valve timing system inside an automobile engine that has a computer chip electronically control the lobes on the engine’s camshifts.  In more basic terms, a computer chip varies the amount of fuel and air reaching your engine to tune for performance and / or gas mileage.

Honda now uses this VTEC engine in almost all of their automobiles, some for performance and gas mileage, and other engines merely to tune the best gas mileage.

A VTEC engine when tuned for performance will allow a 150 horsepower 4 cylinder engine without variable valve timing achieve 190 horsepower or more with the technology.  This power is only realized in the upper RPM’s when the variation switches from normal driving control for good gas mileage to performance level driving.  Sometimes this switch in valve timing is pronounced by the “VTEC growl”, a louder engine sound when the car has changed how it is distributing fuel and air to the engine.

This technology has been popular enough with Honda that in the few short years it has been used, it has gone from being available in only one Honda model (the Acura NSX) to being available in nearly every.  The popularity has now extended to other manufacturers as well including Ford, Porsche, BMW, Nissan, and most recently Toyota with a new version of the Celica sporting an engine extremely similar to the Acura Integra GSR VTEC engine.

 

Common VTEC Misconceptions:

Pro VTEC

1.  VTEC only engages at high RPM’s.

This is perhaps the most amusing of all of the popular misconceptions.  VTEC was designed to be in use at all times by drivers.  In fact, VTEC is actually being used at all times in any VTEC engine.  On the well-known VTEC engines, the VTEC chip controlling valve timing is tuning for good gas mileage at lower RPM’s, and in higher RPM’s tunes for performance.

For example, most people are not aware that the very fuel efficient Civic HX, getting 44mpg, uses a VTEC engine.  It does not have the well known “VTEC growl” (or “VTEC whine”, depending on your perspective and the car), but it has a VTEC engine, none the less.  It uses VTEC to get the greatest fuel efficiency at all RPM levels, all the way to the fuel cut-off, and does not tune itself for performance.  By using computer controlled valve timing, the Civic HX can get far better gas mileage without losing too much performance.

The reason everyone talks about “oh, 4400 rpm is when VTEC kicks in” is because that is when a distinct difference in how VTEC behaves makes itself known with a very obvious sound difference on performance VTEC engines.  The exact point this change occurs depends on the engine, and on non-performance VTEC engines one will never hear the change at all.  In fact, when one is not hearing the difference in the valve timing, the valve timing is still being electronically controlled.

2.  Only racers need VTEC.

Performance VTEC engines have a reputation of only being for racers.  This reputation is built from the fact that automobiles in racing circles tend to have very high RPM engines (like performance VTEC engines), and are constantly driven in the higher RPM’s.  Some people believe that a VTEC engine is not useful below the performance valve timing change, and therefore if you are buying a VTEC car you should be in the higher RPM’s constantly.  By this logic, the only people that need a VTEC car are people that are racing.

Fact is, in most normal daily driving conditions, 0 to 60 times are worthless.  Most of the time a fast zero to sixty time, or quick acceleration is not needed.  The size of the engine is meaningless when caught in bumper to bumper traffic on I-405 every afternoon.  Only when a person needs to pass someone on the highway will power really be needed.  This is exactly why Honda uses VTEC.  Most of us will find a small four cylinder engine with valve timing tuned to fuel efficiency fine for most driving.  And when you need that extra push to pass someone?  Switch the car into a lower gear, let the RPM’s hit the VTEC performance change, and watch your car pass with ease.

Truth is that racers need an engine tuned for the performance VTEC level at all times.  Non-racers need the VARIABLE timing that many auto manufacturers use in their cars so their automobile achieves excellent gas mileage while providing enough power when needed.

3.  VTEC is not usable in normal everyday driving.

As you should now be aware, the word “variable” in VTEC is there for a reason.  The system is working at all RPM levels in a car to achieve many different things based on what the car thinks you need.  At lower RPM’s it tunes for better gas mileage, and at higher RPM’s it tunes for performance.  It just so happens that in normal driving, you will want both of these things, however you will want them at different times.  This is why variable valve timing has become quite popular – because being able to choose between gas mileage or performance is one of the things it does best.

When you are doing your normal daily commute, stuck in traffic, hitting stop lights constantly, and just idly going about your business, you simply want your automobile to get you there and give good gas mileage.  However, when you want performance, systems like VTEC are there to help simply by dropping a gear, and putting your foot to the floor.

4.  Do not use performance VTEC levels constantly.

There are many performance drivers, aka racers, that drive VTEC engines.  The reason is because Honda automobiles are built to withstand constant high RPM driving, especially the performance VTEC models.  The performance VTEC automobiles, like the Acura NSX, Honda Prelude, Honda S2000, Acura Integra, and Honda Civic SI all happily will spend the day near the “red line” of the RPM band making the VTEC growl until you are sick of it.  Driving one of these cars at the red line can be a thrill to the driver, because it gives the feel (and sounds) of actually driving a formula one or other high rpm racing automobile.

These cars are not “muscle cars” and will not win the power engine fight, but they are easily powerful enough to give just about any car on the road a run for the money.  If driven correctly (and VTEC engines do have a learning curve on the driving end because they rely on high RPM’s to perform), some of the above automobiles are easily some of the fastest in their class.

And, on the bright side, when you get sick of racing all day long, they can be driven normally and the VTEC will help to get excellent gas mileage.

4. VTEC is not good in stop and go situations.

It is true that, with the exception of the Acura NSX, all of the performance VTEC engines are tuned to perform in “thrifty” mode at lower RPM’s.  With larger engine VTEC automobiles, like the Prelude, Acura CL, Acura TL, and Accord, there is plenty of low end torque for stop and go even in the lowest RPM’s.  With the smaller engines, such as in the Civic SI and Acura Integra, these cars can seem disappointing at low RPM’s because the automobile has a relatively small engine.

Truth is that these cars take only a second or so to reach VTEC performance mode from stop.  If one switches gears before taking the car to the upper end of the rpm spectrum, the performance is bound to be disappointing.  If one has a second of patience (literally), these cars will happily perform.  If taken to the redline, with skilled driving, these cars will reach the speed limit and beyond very quickly from a stop.  Some of the performance VTEC automobiles are extremely impressive in these situations, and all of them have very respectable stop to 30, and stop to 60 numbers.

However, most of the need for power in daily driving is in passing situations, which usually happen when the car is already moving.  In these situations VTEC is wonderful since all it takes is a gear switch for performance to kick in.  Yes, even in stop and go situations, a VTEC engine will usually please most everyone.

4.  VTEC is an old idea.

Computer valve timing is something that has been perfected for mass production only in recent years, and championed by Honda.  Honda did not invent it, but they did improve on the idea (having the VTEC system change duration and lift as well as timing), and have made the technology somewhat commonplace. In fact, they have forced other automobile manufacturers to design VTEC engines of their own.  Toyota, Ford, Porsche, BMW, Nissan, and others have all jumped on the VTEC bandwagon because the technology has been so popular.  Most owners love the way that VTEC makes their cars excellent for daily driving, and good performance vehicles as well.  As a result, buyers have spoken, and other auto manufacturers have had to start perfecting this tricky technology.  Even though other car manufacturers have started to use VTEC type technology recently, major automobile magazines like Car & Driver and Road & Track have stated that Honda is well ahead in having perfected this technology.

5.  VTEC is a gimmick.

Some believe that VTEC was invented as a gimmick to make small engine, high gas mileage Hondas seem more powerful than they are.  Indeed, some buyers have the misconception that a 200 horsepower Honda Prelude has that amount of power at all rpm levels.  That is a shame.  However, these are the same people that believe non VTEC engines have the same horsepower at all rpm levels.  They simply do not have a firm understanding of how automobile power is measured.  And if someone is buying a car based on numbers without having test driven the vehicle, well, then they may deserve to be in for a surprise.

Yes, VTEC is considerably less powerful at lower RPM’s.  This is on purpose, to assist the car to get as good gas mileage as possible at lower RPM’s.  As we all know, it does not take long to go from the low end of the RPM band to the high end, and when the car does, the horsepower rating changes significantly.  It is not a gimmick, and the power truly does change dramatically.  In addition, if someone needs high power constantly, these cars will happily perform in the upper RPM’s all day long.  Although, admittedly, why would someone buy a Honda that needs performance power all day long?

6.  Only larger engines can benefit from VTEC.

VTEC is useful in all size engines, as can be seen by the fact that Honda VTEC engines have found themselves in the 1.6 liter, 4 cylinder Honda Civic to the 3.2L 6 cylinder Acura TL.  In small engines, it makes an otherwise underpowered car have reasonable performance in the upper RPM’s.  In an already powerful engine, it makes it even more so.

7.  If VTEC is so great why is Honda the only one doing it?

Well, the truth is almost all major automobile manufacturers now either have VTEC of their own or are bringing it to market soon.  The difference is that Honda made it mainstream in their automobiles some time ago and has better perfected the technology.  Honda now uses VTEC in nearly every car they produce, and it is likely other car manufacturers will follow suit.  So, whether you like it or not, it is quite possible your next vehicle will have it.

Anti VTEC

1.  VTEC will make a small engine faster than a big engine.

This is, of course, bogus.  VTEC performance tuned engines can make an engine have more power, but it does not take the place of a larger engine.  If it did, Honda would put their 1.6L Honda Civic SI engine in their Acura TL.  Fact is, if they did, Acura TL owners would complain constantly that their car did not have enough power to pass the Volkswagen Bug next to them.  The heavier the car, the greater the need for a more powerful engine to have the torque necessary to get the car up to the VTEC performance level.  The lighter the car, obviously there is less need for a larger engine.

It is very true that a Honda Civic SI that has been modified with a heavy subwoofer box in the back, heavy 17” rims, a new exhaust system, a super size spoiler, and carries three of the drivers best friends will not perform anywhere near a performance level.  The engine size simply can not supply the power necessary to move that much weight in a short period of time.

However, that same Honda Civic SI with no modifications and two passengers will do just fine performance wise.

2.  Honda invented VTEC.

Variable valve timing has been around for years, both mechanical and computer controlled.  Every major auto manufacturer has used it.  Honda made it mainstream and perfected it for mass produced automobile use, and other automobile manufacturers have since followed suit.

3.  Everyone loves the VTEC growl.

For some the VTEC growl is a “cool” sound when the RPM’s move into the performance end of the VTEC spectrum.  For others it spans from “noisy” to “annoying as hell”.  It is sometimes called the “VTEC whine” because it can often sound, well, whiney, in the smaller Honda engines.  If you are thinking of purchasing a VTEC automobile, make certain you test that automobile at ALL RPM levels before purchasing.  I recommend spending significant time in the higher RPM’s to see if you can live with the sound, because in some Honda models (particularly the Honda Civic and Acura Integra) the VTEC growl is loud inside the automobile as well as outside.  In the Prelude and Accord, it is not nearly as pronounced inside the auto (but is very noticeable outside).  In the higher end Acura’s like the CL and TL, it is barely even noticeable.

The important thing is that an automobile buyer spend significant time behind the wheel of a car to make a proper purchasing decision.  Many dealerships will even allow a buyer to take an automobile out for a few hours or even a day.  Find one and take advantage of their generosity.  You may love the car, but you may not.

4.  All VTEC engines are powerful at all RPM’s.

Some VTEC engines are not tuned for performance at all, so such as the case with the Civic HX, the car is not technically powerful at all.  Performance VTEC engines, like all engines, do not reach peak power until the higher RPM’s.  This is especially pronounced in VTEC engines since they save performance for the higher RPM’s, whereas some other automobiles are tuned for performance at all RPM levels.

5.  VTEC is the greatest thing to ever happen to automobiles.

VTEC is a nice way for some automobiles to get both good gas mileage and good performance, and other VTEC automobiles to get the best gas mileage possible while not hindering performance too much.  Is this the greatest invention ever for automobiles?  Hardly.  It is perhaps a couple notches higher than the fuzzy dice, but I am certain as technology improves, other inventions will make VTEC seem rather inconsequential.