Acceleration!Toyota IQ 1.0L correct oil Viscosity critical

[Andre122]

Regarding correct oil grade/viscosity.  Having driven mostly cars from the mid eighties to 2000's until recently because they were cheap once upon a time for example Escort Mini Capri AlfaSud Datsun Volvo did not care too much about the oil you used, basically there was 10/40.  Just discovered after suffering acceleration issues for a while! complicated by CAT & oxygen sensor issues + (now corrected) that the little IQ 1.0L VVT engine must have 0/20 oil as this effects the oil pressure which in turn effects the VVT system so in effect the 5/30 oil I was using (wrongly suggested by the main search engine)was raising the oil pressure which was giving incorrect valve timing and the higher viscosity made it harder for the engine I suspect the VVT was the main issue.  Having suspected the camshaft timing oil control valve was faulty (so was on the right track) and by chance managed to speak to a franchised Toyota dealer re the camshaft timing oil control valve part number which they apparently can't divulge but thankfully asked me the issue I was experiencing and came back with I bet your using 5/30 which I was.  All I can say is the engine seems allot happier now, it's still fairly gutless uphills which is probably normal and it's done a thew miles but at least it accelerates much better.

[flash22]

The 1KR only really needs a 5w30 when it's in the 85K+ miles range, modern engines run much finer tolerance than the older cars ever did plus the technology has moved on