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These are rock solid internal mufflers that will increase your fuel economy by a minimum of 3%! This muffler also yields in quicker acceleration due to the better air flow design. The QP Internal Mufflers will easily replace your stock muffler and does so without increasing exhaust noise. Grand Rock customers have see as much as a 9.4% increase in fuel economy from this simple modification.IMPORTANT NOTES:
- Please read the engine application section at the bottom of this page before ordering or call us to make sure you choose the correct muffler for your truck.
- Price is per muffler
- This is for only the muffler, not a stack and muffler.
- The QP-5LC will fit into any 5" Diameter 45" long Stack.
Single Stack: Grand Rock does not recommend a single stack setup with the quiet Performance Internal mufflers. Customers have tried it, but the results have not been as good as with a dual stack setup, 3% and lower gains. Give us a call if you have any questions.IMPROVE YOUR COMPANY'S BOTTOM LINE.
- These results are BEFORE quarterly fuel tax payments.
- Figure in for ADDITIONAL savings.
|Grand Rock Company Testimonials|
|*All results below were tested and published by Grand Rock Co, Inc.|
|ENGINE||STACK CHOICE||STOCK 10" MUFFLER MPG||QPM-1051 MILEAGE||MPG GAIN||% GAIN|
|12.7L Detroit 60 Series, 360HP||5" Dual||6.41||6.79||.38||5.9|
|12.7L Detroit 60 Series, 525HP||6" Dual||5.85||6.40||.55||9.4|
|Cummins N14 Plus, 525HP||7" Dual||5.96||6.35||.3||6.5|
|N14, 400 HP||5" Single-Not Recommended||5.75||5.92||.17||3|
|For maximum performance we recommend the following MINIMUM sizes of QP's for your Application.|
|ENGINE SIZE IN LITRE||ENGINE SIZE IN CUBIC INCH||HORSEPOWER RANGE||RECOMMENDED MINIMUM SIZE QP PART#|
|15L||916||up to 400||QP-6LC|
- ManufacturerGrand Rock
- 3% MINIMUM MPG GAIN.
- Quiet Performance Muffler
- 7.28% Fuel Mileage Increase (avg.)
- Much Quieter then open stacks and as quiet as stock. Engine brakes will still be loud.
- Meets Federal and California Sound Levels
- Heavy Gauge, 100% welded construction
- No Turbo Lag, Faster Acceleration
- Easily Installed, Bolts in place
- Patented 2004
- Easy Install! Two holes in each stack is required.
- Tax Deductible- Repair/maintenance of a vehicle used in business is tax deductible.
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