Saab Site Road Tests: NGK BP6ES vs. Champion 300

Choosing the right spark plugs make a world of difference when it comes to ignition and overall performance. About a week ago, I began experiencing strange "lurchy" behavior with my 99 EMS. You know when you're in heavy traffic crawling around 5 MPH or so, and you don't give your car enough throttle and it begins to buck a bit? It was very similar to that sensation. 

After asking for advice from some trusted sources, notably Keith Landau, who also owns 1978 99 Turbo S, noted the likely culprit was due to bad or incorrect spark plugs. He specified that, for some unknown reason, Saab 99s prefer the NGK BP6ES spark plug. These spark plugs feature copper electrode tips and are non-resistor type plugs. 

Prior to this issue, I was running Bosch 6736 plugs, which featured different platinum electrode and resistors from the NGKs. They were rated as OE plugs for Saabs, including most other models in addition to the 99. 

Now, you would assume that I would easily be able to locate a set of NGK BP6ES plugs, but of course, nothing is ever that easy. Unfortunately, NGK no longer makes this model of spark plug! However, a very similar plug, the Champion 300 Copper Plus, was readily available over the counter at most auto parts stores. Like the NGKs, the Champions featured copper electrodes with no resistors. With that in mind, I decided to compare the two plugs to see how well they performed. For each test, I will be comparing how each spark plug set performs during different throttle engagements; Light, medium, and heavy. 

Champion 300 Copper Plus

The Champion 300s, when installed, were already performing much better than the previous Bosch set I had. The engine felt and sounded smoother, and the car seemed much happier with a fresh set of plugs installed. Now to road test them.

Under a light throttle, the car performed as it previously had. It got up to speed decently, and there was no sloppy behavior like I had been experiencing previously. Around town, it was pleasant to drive. With medium throttle on main roads, the car felt once again similar to how it used to perform. It was responsive and got up to speed relatively well. 

I began to notice, with slightly heavier throttle, it became somewhat sluggish, and the real noticeable deficit was highway performance. The car had noticeably lost its confidence in accelerating as it did under light and medium throttle. I was constantly fighting the car to get within the powerband. Specifically, in 4th gear, when it would normally keep going after 50 MPH, the car kind of lost its desire to move any faster than it was already going. It did accelerate, but not without a fight. 

NGK BP6ES

Now came the true test. These were the spark plugs that were recommended by Keith, and had a lot of praise behind them from others in the Saab community as well. Due to their unavailability over the counter, Keith was very generous to send me a set of these from his own stash. Thanks again, Keith! Now, time to road test these.

Under light throttle, the car felt normal and confident. In medium accelerations and driving, I noticed much more confidence in performance getting up to speed than with Champions. Older enthusiasts who had owned 99s in their past, had noted how much of a go-cart the 99 could be. I finally understood what they meant.

But boy, does it get better! Under heavier acceleration, that little B-Motor came to life. There was no hesitation in getting to the powerband, and once it was in the zone, it kept going! The sensation was as if I had unlocked a new performance setting within the B-Motor. It felt that good! So, yes, the NGK myth was true. 

My Final Thoughts

Overall, the Champion 300s are decent plugs. They do the job that's required of them, but under performance and heavy throttle, not so much. If you need a replacement spark plug that's similar to the true OE spec, then I'd say these are fine if you're not looking for sporty performance. However, if you're seeking to find your true car's potential through spirited driving, then by all means, use the NGK plugs. 

Unfortunately, as stated earlier, the NGK BP6ES plugs are no longer in production, meaning you won't be able to find them over the counter at any auto parts store. You can find them on eBay, or by asking around, as they still exist, but you will have to search harder for them.