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GUA B.V. Agreement for Shelby and other Superchargers


These vehicles have been tuned by a professional technician using state of the art technology. A data base has been created of your trucks’ engine capability, horsepower, performance ability and features. 

Failure to follow and comply with the below requirements and guidelines can be easily detected and will void the customers warranty when detected. 




Owner acknowledges that a fuel octane of 98 or higher is recommended for the life of your supercharged vehicle.

Do NOT use less than 98 octane gasoline.

Use of below 98 octane gasoline will cause engine damage and WILL VOID the GUA driveline warranty.


Owner acknowledges and understands they must follow the mandatory break-in procedure listed below.


For the first 1600 km, which includes ALL test drives DO NOT:

1 Accelerate at Full Throttle 

2 Exceed 4,000 engine RPM
3 Tow a trailer or create engine bind from pulling or towing 

4 Operate in/use cruise control. 


Failure to follow the guidelines can cause premature failure to powertrain components and will void the warranty. 




Failure to follow required break-in instructions (including test drives) will void the warranty.

Greater than 180-day old fuel must be completely drained, to include fuel tank and lines. The tank
must then be refilled with new 98 or higher-octane fuel before starting or driving the vehicle.

Use ONLY Ford Motorcraft 5W50 synthetic oil.
Recommended first oil change at 1600 km - then every 7500 km there after.

Spark Plugs

o Exchange every 20.000 km or less.It is imperative to follow the recommended ignition maintenance to achieve peak performance and not cause possible engine damage. 

o Reset gap to.028

Use ONLY Ford Motorcraft Spark Plugs recommended by FORD for your truck year,model,and 

engine size. Again, reset to .028” gap. 

Supercharger Oil must be changed every 50.000 km or less, using Ford Motorcraft #XL-4
Supercharger Synthetic Oil.

Air Filter should be cleaned using K&N Cleaning Kit or equivalent.

The air filter should be cleaned every 15000 km or less, depending upon the environment the vehicle is used in. Dirt and dust are harsh on an engine; therefore, a clean, functioning air filter is critical to the engines performance and life span.

Dealer understands and is aware of the Executive Order and if Dealer markets the product in violation of that Executive Order in applicable law, said dealer agrees to indemnify and hold harmless Fox, Tuscany, GUA B.V. and Shelby from all liability and damages.

All supercharged vehicles require premium gasoline with an octane rating of 98 or higher when available.

Fuel age greater than 180 days old must be completely drained from the fuel tank and fuel-lines. then replaced with fresh fuel meeting a minimum of 98 octane.


Do NOT add octane booster to old fuel. The addition of octane booster will not bring the fuel octane quality to the standard requirement of the engine.

Modifying the hardware or software from Shelby/Tuscany/Fox/GUA B.V. original specifications will void the driveline warranty.

They must have a completed & signed Shelby Supercharger Retail Purchaser Agreement returned to GUA B.V. for the driveline warranty to be in effect and valid.
Until GUA B.V. receives this Supercharger Agreement back signed by Owner, the driveline warranty will not be activated.

If the Owner has a service issue and lives outside of your market area, please contact GUA B.V. at and we will direct them to a local Servicing dealer. 

No other verbal or written commitments from any GUA B.V. representative will supersede the above dealer acknowledgements. 

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