I can honestly say, i have had three SSEis, on third one now...i used Bosch in my first one the first tune up ever, they died after a few months..AC delco OEMs seems to work REALLY well, but the VPower Tr55s i get at a better price, and seem to last much longer in a boosted car, copper is old technology, but its GREAT for the high performance market. I dont even look at another plug when i get them for my cars, its ALWAYS the TR55

I know they made my tired old L27 run allot better! Great plugs at a great price IMO.

On a quick note, the best plugs are the Silverstone spark plugs on the market made by Nology, due to Silver is the best metal for conducting electricity. I have found more power with these sparkplugs then any I have tried. I have tested about every spark plug there is on the market and the best one I have come up and are using at this time is the Nology Silverstone sparkplugs and is very noticable. The others such as Iridium and the copper are good but really unnoticable in performance. Here is Nology'* website and see if you like them. Its really in preference but I do notice a big difference. http://www.nology.com/silver.html

So, what sort of distance are you guys getting out of the standard Tr55 V-powers. I love NGK and I've been using them in all of the family'* various vehicles (several 4 and 6 Nissans, a Caravan, an ancient volvo, etc) since forever and they've never let me down.

I'm willing to fork out the cash for the IX iridium NGKs if it means I don't have to change them for 100k miles. How many miles are you guys managing to put on the standard TR55s before they need changing? For reference, my car is a non-supercharged Series II '95 Bonneville.

cough Cough...wow...dusty old thread there.

Mileage will vary with driving conditions/abuse etc. it'* tough to say...however I'd expect 20-40 with care.