The only way LEGALLY that any dealership can deny the warranty is if they can PROVE without a reasonable doubt that the modification caused the problem with the vehicle.
Read the Magnuson Moss Warranty Act:
http://www.ftc.gov/bcp/conline/pubs/buspubs/warranty.shtm
And, more information:
By Joe Bradley, Manager of Ford's Warranty Analysis department
"As you might expect from the company that formed SVT, the Ford Motor Company has many employees who are true performance enthusiasts -- folks who love and care for their personal high-performance vehicles as much as or more than the next guy or gal. Many of us, in fact, are true "weekend warriors" who can be found at the local drag strip or road course on Saturdays and Sundays, and tinkering under the hood during weekday evenings getting ready for the next event. As automotive enthusiasts, we certainly can appreciate performance machinery.
That said, as Ford employees we all want to do the right thing for our customers as well as for the Ford Motor Company. That is precisely why it is important to have a concise, easy-to-understand policy with regard to Ford warranty administration. For vehicles that are not modified, the Ford warranty policy is clear – the company backs its products within the guidelines of the new vehicle limited warranty, which is designed to protect the customer from defects in factory workmanship and/or material.
However, in the case of vehicles that have been modified, one needs to understand that the modifications may affect warranty coverage. This is simply because any damage or failure of new vehicle components or systems that was caused by modifications to the vehicle are not defects in "factory supplied" workmanship or material.
To illustrate this point, let's consider a small sample of vehicle modifications and see how they might affect factory components or systems: When it comes to changing the factory engine drive pulleys, there are some powertrain system and component concerns that deserve consideration. One would be any electrical and/or charging system problems that arise because of reduced alternator operating speed caused by the installation of underdrive pulleys. After all, the performance and serviceability of many system components are based on certain design parameters that include operating speed. The same goes for problems stemming from higher cooling system temperatures because of reduced water pump flow caused by the installation of underdrive pulleys. Increased underhood temperatures caused by owner-induced changes to a factory design-specification part can have a detrimental effect on any number of powertrain components or systems – some that may have long-range implications. And things can get even more serious when supercharger pulley changes are made, including head gasket leaks and piston and connecting rod failures. Also possible is piston damage due to detonation from improper air/fuel and timing modifications.
The installation of any non-factory forced induction system can also cause problems. Base engines modified with aftermarket superchargers, turbochargers or nitrous oxide injection systems may indeed bring about some power gains, but they can cause piston, connecting rod and/or crankshaft failures as well.
Other parts of a vehicle's factory-spec drivetrain are also susceptible to damage when engine torque and horsepower is increased. Performance chips or other power-enhancing devices increase torque loads on the driveline and can force failure of the transmission and/or rear axle. The latter problem can be especially true when owners switch to wider tires or racing slicks in an effort to increase traction. Even non "go-fast" aftermarket accessories such as remote starters, alarms, supplementary gauges and audio equipment can cause electrical system service problems if they are installed incorrectly or have improper connections.
When it comes to fairly evaluating the possibility of a warranty denial, there's one simple rule of thumb to follow: Although the installation of non-Ford parts and aftermarket modifications, by themselves, will not void the Ford New Vehicle Limited Warranty, failures that result from these parts and/or modifications may result in a denial of warranty coverage for such failures or damage.
The bottom line is, Ford Motor Company wants each of its owners to enjoy their product to the fullest extent – and that includes performance vehicles. But dealer service technicians have seen, and continue to see, that modifications may cause the original design to fail. The addition of aftermarket parts is a risk that each and every vehicle owner must evaluate for themselves. All that's needed is a reasonable dose of common sense. When and if you modify your vehicle, please consider whether the modification may cause another component to fail – and if it does, recognize that warranty coverage for that failure or damage will likely be denied. "
And, read the vehicle manufacturer warranty section in this article, which is almost 4 years old:
http://www.usatoday.com/tech/news/internetprivacy/2004-12-27-auto-blackbox_x.htm
...and one more:
http://www.edn.com/index.asp?layout=article&articleid=CA529380
This law was written to protect the public against vehicle manufactures demanding that only their consumable parts (oil filters, oil, etc.) could be
used, or the warranty was void. Bottom line, you can use a Purolator oil
filter, instead of a Motorcraft oil filter and your warranty will not be void!
"Performance" mods are a different story, period, as stated by Joe Bradley!
A little more detail:
I’ll try to make this as short as possible so please bear with me. First, I am not expert and this is ONLY my opinion based on reading not only the Magnuson-Moss Warranty Act but many other articles written based off of it.
The Magnuson-Moss Warranty Act was intended and is intended to protect the consumer, the person who bought the vehicle, from the manufacture dictating to them, the consumer, that they MUST use the manufactures oils, filters, belts, tires, etc, the list goes on.
Now, a manufacture can FORCE you to use only their parts BUT if they do they, the manufacture, must supply it to you free of charge and free of any labor cost. That is the very short version of the Magnuson-Moss Warranty Act.
The “Act” will NOT protect you if you install “performance enhancing” parts, such as a supercharger, nitrous oxide, suspension kits, etc. The reason is when you install those kinds of parts you are in fact “altering” the original design of the vehicle and frankly I would stand side by side with any manufacture in any court and take their side.
No one has a right to alter the vehicles original design AND then expect the manufacture to warranty items rendered defective because of said parts. For example if you install a supercharger and blow your motor, transmission or rear-end tough luck that’s your fault and NOT the manufactures.
With that said, the above example would ONLY render your power train warranty invalided but none of the rest of the warranty. People look at the warranty as a complete package and it is NOT, it has many entities to it such as electrical, suspension etc. While one may be rendered invalid the rest is not.
Personally I hope no manufacture would ever have to pay for repairs to someone’s vehicle that puts on a cold air intake and then blows the motor because of a lean condition. If the manufacture was ever forced to do those then guess what? We all pay for the dummies who know nothing about properly tuning a vehicle. Trust me the manufacture will indeed pass that cost along to everyone in the form of higher vehicle prices.
The Magnuson-Moss Warranty Act is ONLY FOR aftermarket parts that MEET the manufactures specifications. If you use the wrong motor oil that does not meet Ford’s specifications guess what? You out of luck because you just voided your warranty for failure to use the PROPER specified parts.
The Magnuson-Moss Warranty Act is NOT and has NEVER been for aftermarket PERFORMANCE INHANCING parts.
FORD CLEARLY STATES THE FOLLOWING:
From the Ford Cars and Light Trucks 2006 Model Year Warranty Guide (June 2005, Fourth Printing) page 8:
Not covered by the warranty:
”Damage Caused by Alteration or Modification
* alterations or modifications of the vehicle, including the body, chassis, or components, after the vehicle leaves the control of Form Motor Company.
That right their my friends should put everybody’s mind to rest because ANY alterations or modifications will void that part of the warranty. Cold air intake, tunes, programs then kiss the power train, transmission and rear-end warranty bye-bye. Lowering kits, kiss the suspension, possibly the transmission and rear-end warranty bye-bye etc…
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