2007 Hyundai Sonata There Real Difference Engine Oil Spec Purchased 5 30w On

it does matter. stick to the 5-20 oil.

Roy

I made a mistake on the mileage. It is 56400 NOT 566400. (Sorry)

Waynestorm

There is very little difference between the two oils you mention and contrary to what some have said. It may mater when breaking in the new engine as the manufacture test the engines for best performance oil NEW engine.. But there are many things after that that will depend on what weight oil to use..Example>> TEMPERATURE IS THE ENGINES DESTROYER>>>temperature where the you live,hot climate would suggest heavier oil like 10 -30 or even 50 while colder would suggest lighter like 5-10/20 Plus the mileage the higher then heavier like 10 -30/40 or the oil sold as high mileage engines.This to make sure in all climates engine oil will can be pumped all through the engines ports and insure proper lubrication...All that said you should use the SUGGESTED manufacture oils but not necessary to be exact..especially with the new cleaner of today

Thanks for listening

Sam railroadsam@pennswoods.net

what worries amnufactures and why they want or reccomend the weights is the ability to lube as fast as possible to the top end of the motor. when the weight is changed, the time is longer resulting in pre mature engine wear.

Roy