so hondas generally call for 10w-30 motor oil? my question is, down here in aus, it gets quiet hot during the summer, it can get to 45 celcius (113 fahrenheit) i do alot of uphill driving and my cars got quiet a bit of meilage, im not worried about the 10w cos it doesnt get that cold down here so morning starts arent a worry, but wont a 10w-30 thin out way too much under normal operating temperature given how hot it gets here? wouldnt a 10w-40 work better?

 

For Information: my 02 civic started oil changes using mobil 1 5-20 I live in Palmdale ca. temp is from 10 to 117 ( winter to summer ) now with 170k miles + I use mobil 1 5-20 no problems with the engine. I asked Robertsons Palmdale Honda the dealer I got it from and the service manager says continue to use the same oil.
My 07 Fit with 80k is still on the same type oil. no problems to date.
Both cars have been up to the ski areas to transport skiers ( in snow )
Ask your Honda Dealership what they recommend for your car.