Home » Ignition Systems » Do Wider Spark Plugs Gaps Increase Gas Mileage Do Wider Spark Plugs Gaps Increase Gas Mileage Does increasing spark plug gap above factory specs increase gas mileage? If so, what amount beyond factory on average gets the best improvement in mileage? Tags:Factory Specs, Gas Mileage, mileage, Spark Plug, Spark Plug Gap Related Questions My Truck Says It Has Multiple Misfires. This Is Stooping It From Passing Inspection I changed the oil, spark plugs, cables, distributor cap and rotor. The only thing I can I might pick up the coil or the ignition coil to think. Someone Car Problems. Help I have a 92 charade, 1 3L, 3 Zyl.Es was jerking accellerating in the second and 3 Course the more so if one as down hill (felt like a Answers for The Question itsthewill no, doesn’t help gremlingts no, not wider gaps necessarily , they are just there for high energy systems versus the older points-based system, which had lower voltage coils and couldn’t jump the bigger gap. If you get a MSD unit ( Multiple Spark discharge ), you can have your plugs fire 2-3 times each stroke, which will help reduce mis-fires, and WILL improve gas mileage a little bit. They can be costly, and might require computer chip reprogramming in your car/truck, but it is one of the few spark changers which WILL help a little. Another change is positioning the spark plug so that the finger which extends over the center electrode is not blocking the intake valve discharge. I don’t know how it is possible to line them all up, depending on the threads, but hot rodders have marked them and then shimmed them so that the rear of the side finger won’t block the air and gas flow from the intake valve, which gives it a clear shot at the spark. A VERY picky point, but I suppose it could affect gas mileage on a few cylinders that way. And so minor, but when you need 1-2 extra HP out of a 1,000 HP mega-motor, I guess any small advantage is STILL an advantage. – The Gremlin Guy – mdk68gto a gap that is wider than spec can lead to a misfire or premature failure in the ignition system. Incoming search terms: Wider Spark Plug Gap,What Would A Larger Than Spec Spark Gap Do?,What Does Having A Wider Gap On Spark Plug Do,Spark Plugs Affect Gas Mileage,Spark Plug Gap Affect Fuel Mileage,Rra8mx Spark Plug Gap For Mileage,Increace Spark Plug Gap,Does Bigger Gap On Spark Plugs Equal More Power,Dodge 318 Engine Does A Bigger Spark Plug Gap Give It More Power,Bigger Sparkplug Gap Leads To More Fuel Burn ?