0w-30 vs 5w-20 oil for 08 Civic?

[regor]

Manual (and fill cap) recommends 5w/30 oil. However, 0w-30 would be thinner, producing better mileage.



What problems could come about switching to the thinner 0w-30 (Mobil-1) vs 5w-20 (Mobil-1)?



Could the thinner oil void the warranty?



Thanks

[Bror Jace]

regor, are you sure about that 5W-30 recommendation?

My 2006 Civic LX requires 5W-20.

And, at temp, a generaic 0W-30 is the same weight as a 5W-30. The difference between the two is that the 0W-30 is thinner in the cold.

[Duffman]

0W30 is only thinner when cold (when oil is thicker anyway). Go for it, should only be better.

[thebrad]

I am pretty sure Honda issued a TSB regarding this issue, saying it was safe to use 0w20/30 in place of 5w20/30 in select applications. I was unable to find it though, I do however know for a fact Toyota issued one (which I can access).

[regor]

ny error. It is 5w-20

[Bror Jace]

regor, at least you know now. The 0W-20 should give a tick better mileage as it is thinner when cold ... so you may be getting better economy (less resistance) when you first start out.

However, once up to temp, the theoretical differences between these oils (5W-20 & 0W-20) disappear. The one that will give the best economy may be the one that shears down the most ... and I'm not sure engine wear will still be acceptable.

Oh, and I am not a fan of any of the additives you cite in your signature. Want to convince me to change my mind? Do a UOA on your oil and show my low or normal wear to go along with your mileage record.

Some additives contain chlorine or a derivative that causes wear/oxidation initially ... but that coating is then very slippery ... for a while. PTFE has similar disadvantages. Like I said, a UOA will confirm this.

[regor]

I might have tried those other additives, but the only one that has worked is Tufoil. I can remember my 98 Dodge Ram that had the legendary knocking. For those of you who don't know what I'm talking about, the knocking literally sounded like 2 sledge hammers hitting each other at full force. Dodge said that there was no damage being done. Shortly before I won my lemon law suit, I put in Tufoil, and amazingly, it solved the problem, made the truck run smoother and MPG went up.

[spyderbite9001]

hey guys, i havnt used any additives to my civic, but we've added it to my dads yukon xl, and believe me. slick 50 is the way to go. we've also been running it in my dads 82 tercel, since the late 90's and when we had the engine rebuilt, the guy complemented us on how little the engine had degraded, he said the tolerances were so close to original that he installed factory seals on the pistons, not bad for an engine that had 280,000 at the time.

we also used to know a chemist that worked in lubricants for nasa, and theres a chemical in slick 50 called PTFE, its on the label. that chemical is by far the best lube out there, not only that, but it maintains the life of the seals and reduces friction on the crank.

you guys may still be skeptical, but i'll be using slick 50 on my civic.
btw the yukon gets another 2mpg and the tercel gets another 4 mpg with the slick 50 added at the oil change.