Toyota Repair: Question about Corolla and Oil, oil pressure gauge, coolant temperature

Question
Hi Ted,

I live in Fort Lauderdale, Florida, and I have a Corolla '94 that's now 103 K miles. I've always taken good care of it and keep it in very good condition.

I've been using 10W30 oil for the engine, but the last time, I put 10W40 and I've been noticing that the Oil Pressure indicator on the dashboard stays lower (closer to the Cold side) than before for a longer time, as though the car never fully warms up. Is that good or bad for the car? Which density oil would be appropiate to use?

Thank you in advance,

Richard

Answer
I don't quite understand, is it the engine temperature gauge that is reading lower or is the oil pressure gauge lower than before, the temp gauge measures coolant temperature, there is no oil temperature gauge only an oil pressure gauge if so equipped, let me know which it is so I can answer your question.