10W40 has not been recommended for cars for many years due to the waxes used
to extend it to 40. What year car? You should be using that recommended in
the owners manual and listed in stickers under the hood. The only reason to
user higher viscosity is in a worn out engine to slow down consumption.

<suyashsen@gmail.com> wrote in message
news:4c2a55bb-f569-44b2-b1f1-850127247e4e@2g2000hsn.googlegroups.com...
>I have been using 10 W 40 engine oil for my car. I had asked a car
> mechanics for this. I looked up www.hotaccord.org today. One of the
> post there suggests 5W/30 for car engine. I wonder what other accord
> owners using?