I recently purchased an '05 Grand Caravan with 55k km which has a 3.3l engine.
Chrysler calls for 5W-20 weight oil for all temperature ranges but wonder if this is necessary.

An acquaintance who is a licensed auto mechanic says it is perfectly fine to use 5w-30 weight oil but he is a general mechanic with no Chrysler affiliation.

5w-20 oil is difficult to get in our rural area and the much lower cost of 5w30 allows for very frequent oil changes.

Any pro opinions on this?

 

Normally I say go with what the manufacturer states, but going to 5W-30 will not harm your motor or warranty Greg.

 

My wife has an 03 merc sable w/3.0 that we bought about 4 yrs ago at 20k miles. The book calls for 5w20 but I'm a little leary of such a light weight and have always put 5w30 in it. 80k later the motor still sounds fine.

Supposedly the lighter oil gives you better fuel mileage but I've not noticed any difference - it had 5w20 in it when purchased.

 

As a factory trained mechanic when I questioned this 8 years ago and I was informed that the reason for 5w-20 is fuel mileage, It might not matter on 1 car but when you have a half a milion cars it makes a difference,also (i was told) that with computer controlled manufacturing equipment the tollerences are closer than before so the need for a heavier weight oil is not needed.
you can use either one it's not going to hurt your engine.

 

I'm late on this but you are correct. Thats one reason why Ford also started using 5w20 instead of 5w30. Ford had to increase gas mileage to meet the requirements and that's how they did it.

 

5W30 it is then .
Considering I have never seen 5w20 go on sale I can get major brands of 5W-30 for nearly half the price.