mazda 3 oil weight

[kms1990]

i have an 08 mazda 3 2.3L and it is speced to use 5w20 oil in the usa but says mexico uses 5w30 the turbo versions all use 5w30 as well. now i live in texas and i picked up some 5w30 castrol gold edge with titanium for a steal on clearance. i use regular black castrol edge and i put 5w20 in my only change since i have bought the car a few months back. is 5w30 alright to use? if so, what effects other than ever so slightly lower mpg might there be? and if i should not use it why not?

i have searched for this on several forums and google and i am not getting what i should be out of my searches and most of the threads end up degrading into back and forth bickering and nonsence so i want a straightforward answer form people that have more experience with this motor than me and can actually answer my question

 

[concept]

If your owner's manual does not include 5W-30 as an alternative, I'd stay with 5W-20 and sell the 5W-30. The only way to know for certain whether engine life is negatively affected from the use of 5W-30 would be by running a long term test in which there is only one variable - the viscosity at 5W-30. Lots of Mazda 3 owners have piled on the miles using 5W-20 but far fewer have done the same with 5W-30. Even if they did, there's almost no chance that all other conditions were equal.

That being said, I also believe that the chances of your engine failing during your span of ownership after using 5W-30 synthetic oil is very minimal.

 

[kms1990]

i realized i forgot to mention i was only going to use 5w30 for 1 6000 mile change interval (if i end up using it) so i would go back to the castrol black edge 5w20 the change after and from there on out. i just could not pass up castrol gold edge for the price of store brand conventional oil

 

[concept]

I'd say that it'd be harmless, especially in Texas.

 

[leftoverture]

Always follow the recommendations in your owner's manual.