is Energy savings II motor oil better
 

I recently changed my oil and accidentally did not use energy savings II motor oil since then my MPG has dropped at least 4 mpg. I have also been using my a/c alot and not driving as slow as I could. But I do believe that the oil is significantly affecting my mileage. has any one else ever experienced or noticed this.

What specific oil were you using and what are you using now? Brands and weights would be helpful.

Switching from a 10w-30 to a 0w-20 SUPPOSEDLY gives better mileage. I am actually in the middle of a test right now to prove/disprove that point. I should know the results within a couple months.

You could always just dump the oil (into a container and then properly recycle it!) and then refill with the proper Energy savings II oil that you used before. Kind of a waste of money, but you have to think about how much more you will pay for gas using the non FE-enhancing oil...

I don't think you should see a 10% drop in FE because of the oil. Here's a interesting PDF on oils certification. The lowest viscosity energy saving oil will give you around 2%. Did you use a straight weight or some kind of 40w muti weight oil?

The link in the previous post will show what kind of increase in FE is required to make the energy conservation requirements.

Eh? A straight weight oil?!? They still make that stuff?

BTW, your link doesn't work, it just gives something about Mastercard not being logged in...

I just have a hard time believing that you would only see a 2% change in FE from using a lower viscosity oil. I have spoken with too many people who claim otherwise. Then again, that is why I am trying it for myself. The next couple fillups will tell the story for me.

Fixed the link.

Here's some straight weight oil for you great stuff. I used to use the 30w but have switched to the 15w40. IMO tank to tank testing is not going to be accurate enough to tell what kind of benifits your going to get from it. The API has to meet the standards so they use a lot better protocol. YMMV

I have a hard time believing that you would see more than 2% change.
I have tried everything from 20w-50 dino to 0w-20 syn. in my sable.
BTW, my best tank ever was with 20w-50. YMMV;)

Huh, well it is good to be getting lots of feedback on this topic. Makes me wonder what the OP is up to...

Elf: As for the 20w-50 being the best performer... wow. Unbelievable! Not that I don't believe you, it is just that that is unbelievable!

Zpiloto: You make a good point. The API probably does use a better protocol. Then again it could be horribly outdated and not suited to take advantage of the oil in the ways that the manufacturers intended.

In the end, both of you finished with a nice four letter combo: YMMV. In the end, this is what it comes down to. There is no real one answer, as there are too many factors to consider in determining FE.

I have a pretty steady driving technique down, and my traffic conditions don't change at all... so I believe that I will be able to see whether my 0w-20 is going to be able to provide results for me.

One thing for sure though, cold starts ARE improved, no doubt about it!!! A lower weight oil in my engine means the engine turns over much more smoothly and quickly.

Yes, I had some 20w50 in my 87 ford escort, and one cold winter day it wouldnt start. I finaly did get it started, and changed it to 10w30. Much better starting...

Erdrick,

The oil was the same 10w-30 or 5w-30 which ever is recomended It just was not energy savings II. But it was some cheap oil from wal-mart and thats what I get for shopping there but I had been meaning to change it for while and was running out of time. Anyway I will change the oil in about another 1000 miles and I will know for sure.