I had two of them already!... i climbed the "El Avila" mountain... fairly easy, but it asks a lot from the engine (and i did it with 7 cils. as one of the S. plugs disconnected). And also towed my brotherīs Cherokee from another town to our house (i ended up towing him with only 2 cils. connected!... uphill!).

P.S.: I will change this spark plugs ASAP!!!