They have been on my Ford Expedition for over a year (approximately 10,000 miles). No problem. The last set I used (non MSD) lasted maybe six months before a coil died. I don't know if this directly affected my mileage as I installed it when I locked up the cam phaser so my highway mileage went from 18/19 to around 16/17. The decline can have many reasons. I will basically say it was due to a clog and NOT coil packs.
Gooacc 50Pcs Hood Insulation Retainer Clips - Perfect Replacement For Grand Cherokee, Dodge Ram, Chrysler PT Cruiser, Plymouth Laser, Neon - OEM Part Number: 4878883AA
33 Review
820Pcs Car Push Retainer Clips & Fasteners Assortment - Ford GM Toyota Honda Chrysler BMW Benz Nissan Subaru Audi Mazda
32 Review
25Pcs Fender Liner Screws For Toyota Avalon Camry Corolla Scion Lexus - OEM #90159-60498
35 Review
Upgrade Your Mazda MX-5 Miata With CravenSpeed'S USA-Made Door Bushings
39 Review