1. Champion 3013 Platinum Power , pre-set gap is 0.06

2. Bosch 6704 , pre-set gap is 0.040

Most plug mfgs indicate 0.06 gap, why Bosch @ 0.04??????/

Why the difference?

 

The Bosch plug is probably used/designed for vehicles that have a 0.040" gap spec and also happen to fit your car. I'd use a plug designed for your car that doesn't need a large gap adjustment. I'd look for an NGK and nothing super, awesome, spectacular, greatest, mileage improving, smoothest running, best acceleration, new and improved version that gives an under the hood fireworks display controlled by the latest app, just the basic plug.

 

 

Sounds your an advocate for NGK.....

NGK 3403 @ 0.06 gap. 3 bucks a piece. Just curious about Bosch being different, they are the only mfg that is different.....

Thanks.

 

Do you have a factory service manual, or at least a Cheater's guide? Set it to the OE spec. GM used huge spark plug gaps (.080) in the late 70s in an attempt to reduce emissions.

 

Yes I do like NGK, I'm guessing Bosch uses that plug for multiple applications many of which call for 0.040" gap.

What is your '93 gap spec?

 

Which engine ? 3.3 or 2.2 ? Personally I have always used AC Delco plugs in GM products.

 

Isn't there a sticker somewhere in the engine compartment along the cross member that gives the engine specs for the car?