I just put a set in my Paseo that I got for testing. I'll let you know what happens. So far they don't fit correctly though. They are too tall. The others that have also gotten them for testing have seen no real gains. Its not looking like this tank is anything special either, however its only halfway through.
I have not seen any gains either, on my 5th tank of gas with these plugs, no fitment issue on my civic.
I've tried other plugs as well, like the Bosch +4 and I did have trouble with my civic not running as smooth with those plugs.
I plan to switch back to NGK copper core v-power plugs that are recommended by Honda next time I change plugs, I've always had good luck with them.
In sohc engines(like my old metro and escort and dads jetta) i saw the best improvement with autolite platinum plugs. They are cheap from walmart and worked well. Bosch have a wierd thing where the way they route the spark tends to slow it down very minutely, but enough to basically retard the timing so anything i have tried those things on have lost alot of power and mileage. On the dohc(my civic si and my g/fs old tracker) i saw the best gains with ngk iridium plugs. My scooters and mothe rin laws bike run best on iridiums as well(i think its the fact that the tiny electrode doesn't get as dirty because it's so small). But those are my findings so far. Haven't tried pulstar though.
They had an episode of Horsepower TV on Spike that tested these plugs vs. the standard plug. To test they ran the engine on a dyno the let everything cool down and run again with the pulstar plugs. The results fuel wise was minimal but they did gain 2 hp and 1.5 lb/ft. With that being on a Chevy 350 I doubt the plugs will make any diffrence on a 4 banger.
2hp, 1.5 torque? That's less than 1% on a V8. That's easily within the noise of testing variations. Add in the fact that these are EXPENSIVE, and it's clearly not worth it.
