In the USA the recommended interval to change spark plugs is 120,000 miles. In Europe it is 90,000 km (56,000 miles). Does anyone have any insight in this massive difference? And do people in the USA actually change them only every 120,000 miles or do they (need to) do it more often? 56,000 miles is already a long interval, I suppose the use of iridum plugs (which are also recommended in Europe, Denso SC20HR11 is mentioned in the owner's manual) is what makes this possible?
Iridium plugs are the reason . I have been pooling my plugs with egr circuit cleanse as the windshield wiper cowling comes off and it makes the plug job 10 minutes . I’m doing the circuit cleanse every 50k miles or so, which means the plugs will be every 100 k miles after their original change at 120k miles. Hope that helps.
Well, Iridium plugs are also what's used in Europe, so that doesn't explain the difference in the interval. I've had a look at a US manual for 2011 and it lists the exact same spark plug as the European manual.
To further confuse things: In small print in the 2010 ,2011 and 2018 maintenance manuals it says that the spark plug replacement interval for California and some other states the interval is 150,000 miles. I haven't looked at other years. In the Rav4 hybrid and gas versions the interval is 120,000 but only says that changing plugs is required for the emissions control warranty, not that the interval is different for California.
I just replaced the plugs with the original (SC20HR11). At 132,000 miles they came out looking great.
I planned to replace mine at 75,000 miles because I experienced a few rough, cold start ups. It may be the whole EGR and intake thing, unfortunately... No oil catch can yet.
For me, the rough cold starts seem to happen most often/worst after I push the on/off button while the ICE is still running. I saw it mentioned here on PC somewhere that it's best to wait for the car's computer to shut the ICE of manually and then power down via the on/off button. I have tried to follow this whenever possible and I personally believe it has reduced/eliminated the incidents of the rough startup.
It’s either that, or you get the rough startup if you switch off before the engine completed warmup. But if the engine is warmed up, it won’t be running when you switch it off. I had this issue with my 2010 Prius. I sold that car in 2012 and bought one of the first Plug-in Prius cars, and it doesn’t have the problem. So Toyota fixed something in 2012.
Mine is a 2011, so it's entirely possible. If they hadn't fixed it with whatever they did in 2012 I'd almost like to be able to turn the switch off and get out lock the car etc. with the ICE still running and then have it shut itself off when the right conditions were met, similar to a turbo timer.
