tsikoteers,

im using regular ngk plugs and castrol 15w-40 motor oil... if i change to iridium plugs and 10w-30 motor oil, would it improve my fuel consumption? i was thinking kasi maybe 5w-40 would be a bit to thin for a 10 year old car, or is it?

AFAIK motor oils contribute to better fuel mileage, do spark plugs have the same effect also? befor kasi i used bosch super four & to me it felt kinda "malakas sa gas" or is it just me?

thanks!