On the contrary to popular believe that all plugs makes the S10 gives the same performance, I can testify that the NGK G-Power range of plugs, platinum tip with projection, CPR8EAGP-9 gives better performance, better fuel economy and top speed. I had tried Denso Iridiums IU-24 and the performance and fuel consumption deteriorates. Please don't waste time with the IU-24 which has no projected tip. The projected tip is very important to performance.
I took my S10 on a 1400 km round trip, Penang, Malaysia to Phuket Thailand on the hottest months. I never once use S mode, T mode all the way and keeps up with KTM 1190, R1200GSA LC. Never sluggish, never lagging, and I was carrying pillion and 3 loaded boxes while the KTM'ers and GS are all single riders. T mode is about 80% of stock S mode, while S mode, I have to be very careful on the throttle. No pinging, knocking, pre detonation even when it was really hot (stuck in a traffic crawl for about 30 minutes, almost non moving and oil temperatures were above 105 degs C).
To date, 4 S10 in Malaysia are using this plug and all gave the same conclusion, T mode is near S mode type of performance. One rider says his top speed was 207 kph, and with the Platinum, it can do 212 kph and he just found out (today) his air filter is super dirty.
The bad: For the non-south east asian countries, this plug is not available. It does not come with the terminal nut, so we have to source it from other plugs.
Price I paid for this plug, less than US$5.00.
For injector's cleaning, a 500 parts to 1 TCW3 2T Outboard fuel-oil mixture does the trick to clean up carbon deposits.