Is Mobil 1 10w-40 ok in my engine?

[otterby]

Im sorry to post another engine oil question but I need some input. I've always used Volvo Penta 30wt synthetic in my 2005 5.0 Gxi-E. I see now that Volvo only sells 10w-40 which I assume is a suitable replacemnet for the 30wt. My question is, Is there any reason I couldn't use Mobil 1 10w40 (High Mileage) instead of the Volvo 10w40. I know Mobil 1 is an excellent product for my car but is it ok for my boat. I would gladly use the Volvo oil but I have to buy it online and I can get the Mobil 1 at the local WalMart.

 

[Don S]

Re: Is Mobil 1 10w-40 ok in my engine?

Moving this to the Non repair forum with all the other oil threads, and there are lots of them. All saying the same thing, if you don't want to use what the manufacturer suggests, then use what ever you want. All you will get is what each person likes.

 

[Bamaman1]

Re: Is Mobil 1 10w-40 ok in my engine?

Check Bobistheoilguy.com for the best website on motor oil. It's a wealth of knowledge for anyone into cars/trucks/boats/pwc's.

It's a pretty complicated subject. Great things have been said about Mobile 1--even when compared with other brands of synthetic oils. You can read for hours on this subject.

 

[otterby]

Re: Is Mobil 1 10w-40 ok in my engine?

I've found a Mercruiser 20w-40 full synthetic oil locally. I'm thinking this would be a good replacement for the VP 30wt synthetic. Any thoughts?

 

[Another retired guy]

Re: Is Mobil 1 10w-40 ok in my engine?

I've found a Mercruiser 20w-40 full synthetic oil locally. I'm thinking this would be a good replacement for the VP 30wt synthetic. Any thoughts?

You say you've always used straight 30. Is that what Volvo recommended for that engine? If you won't use the recommended oil then everyone will have an opinion based on their experience! Having said that, I would say that a 20-40 synthetic would be a reasonable substitute for a straight 30. I personally wouldn't use a 10-40 in an engine that was designed to use straight 30. As a general rule you would use a heavier weight oil as the engine ages- not a lighter one.

 

[Howard Sterndrive]

Re: Is Mobil 1 10w-40 ok in my engine?

VP likes to put engine oil coolers on everything, which is why they call for thinner oils. I think 30wt was way too thick for a VP with an engine oil cooler.

 

[Don S]

Re: Is Mobil 1 10w-40 ok in my engine?

VP likes to put engine oil coolers on everything, which is why they call for thinner oils. I think 30wt was way too thick for a VP with an engine oil cooler.

Volvo doesn't put oil coolers on GM engines any more than Merc or even OMC did.

30W is only one of the weights Volvo recommends.

This is from the owners manual for the E model Volvo the OP has.

 

[otterby]

Re: Is Mobil 1 10w-40 ok in my engine?

This oil stuff gives me a headache. The manual says not to use 10w-40 unless the other grades aren't available. Volvo then discontinues the 30wt and says 10w-40 is the replacement. It must not have been that bad. Oil thats 30wt at temp is good, oil thats 50wt at temp is ok but oil thats 40wt at temp is not recommended, until now?

 

[Don S]

Re: Is Mobil 1 10w-40 ok in my engine?

Volvo then discontinues the 30wt and says 10w-40 is the replacement.

Where does Volvo say to use 10W40? Granted there idea of what oil to use is just all over the map and no one knows what to use. Just have never seen where they say to use 10w40 in the newer engines?

 

[otterby]

Re: Is Mobil 1 10w-40 ok in my engine?

I guess they didnt say to use 10w-40, I've only read that online. I've always bought all my oil at the Volvo Penta Store online. They've only had one choice in the past of synthetic engine oil and that was the 30wt. That was fine because thats what was recommended for my boat. This year when it came oil time I went to the store and the only oil available was the synthetic 10w-40. I googled the topic and read in a few different areas that volvo replaced the 30 with 10w-40 therefore assuming they must be recommending it seeing as thats all they offer now.

 

[doyall]

Re: Is Mobil 1 10w-40 ok in my engine?

Mobil 1 15W-50. Have a buffer against fuel dilution thinning and mechanical shearing, both of which are real life occurrences in marine use engines. Probably wind up with an at operating temperature viscosity of 30 in the end.

 

[KX6D]

Re: Is Mobil 1 10w-40 ok in my engine?

This oil stuff gives me a headache. The manual says not to use 10w-40 unless the other grades aren't available. Volvo then discontinues the 30wt and says 10w-40 is the replacement. It must not have been that bad. Oil thats 30wt at temp is good, oil thats 50wt at temp is ok but oil thats 40wt at temp is not recommended, until now?

A straight weight 30 is usually classified as a "Heavy Duty" oil which may be why VP recommends it for Marine use. Now we have the "NMMA-Approved Motor Oil" which is supposed to handle the water better. Boats ran fine for years without NMMA oil!

I use another kind of "Heavy Duty" motor oil. Most will agree...some will not. I use Chevron Delo-400 15W-40. Its a heavy duty oil designed for the diesel industry and also rated for automotive use. It works great in my and many other's boats! YMMV.

If I had a new boat under warranty, I'd use what the MFG says. As soon as it was out of warranty, its Delo-400 for me! There are other excellent oils out there too! I only use Mobil-1 Extended Version in my Jeep Rubicon due to the lack of ZDDP in regular Mobil-1.

Again, YMMV!

 

[ciscokidd]

Re: Is Mobil 1 10w-40 ok in my engine?

good feedback here I thinking to use 15w40 Rotella T synthetic, however when I called a Volvo Penta shop they said 10w40 is called for my application being a 2000 5.7GS, however I have used this Rotella T 5w40 synthetic in link below in my motorbike which also calles for 10w40, cbr1100xx and it has been excellent and highly reviewed, can not really see an issue using it in a boat motor??...
http://www.bluewaveenergy.ca/LinkClick.aspx?fileticket=k7Cb9r_BkR8=&tabid=259

 

[Another retired guy]

Re: Is Mobil 1 10w-40 ok in my engine?

good feedback here I thinking to use 5w40 Rotella T synthetic, however when I called a Volvo Penta shop they said 10w40 is called for my application being a 2000 5.7GS, however I have used this Rotella in my motorbike which also calles for 10w40, cbr1100xx and it has been excellent and highly reviewed, can not really see an issue...

If the Volvo shop says to use 10/40 why not use it? Why call them if you're not going to follow their recommendations?

 

[ciscokidd]

Re: Is Mobil 1 10w-40 ok in my engine?

If the Volvo shop says to use 10/40 why not use it? Why call them if you're not going to follow their recommendations?

I asked them to inquire, mechanic says originally they said 25w40, he recommended 15w40, i have opted to go with a specific brand 15w40 that bitog has only had good things to say about. i was just curious why 25w40 became 10w40, in between can't hurt right nor can a full synthetic

Reading more on oil it appears Rotella 5w40 T synthetic is an even better option than conventional Rotella 15w40

 

[Another retired guy]

Re: Is Mobil 1 10w-40 ok in my engine?

Reading more on oil it appears Rotella 5w40 T synthetic is an even better option than conventional Rotella 15w40

I would be concerned going with an even lighter weight oil than the new Volvo recommendations. Typically, as an engine ages, a slightly higher viscosity is better than a lower one. If you're convinced the Rotella is the one for you, then go with the 15w/40. ( My opinion anyway! )

PS. Re your original question - you don't have to use Volvo oil, any major brand of 10w/40 will work fine!

 

[Bamaman1]

Re: Is Mobil 1 10w-40 ok in my engine?

Like I said in my earlier posting, see BobIsTheOilGuy.com for postings on marine oil.

Mobil 1 has never received the marine oil code because they have never paid the sanctioning body to put their oil through a very expensive testing procedure. It would easily pass, however. Sales of motor oil destined for marine engines is not even knee high to the oil sales that go into autos/light trucks and diesel engines.

The original question was is Mobil 1 acceptable. The answer is that yes, it will work. It's universally accepted as being one of the best. Castrol synthetic doesn't have as good of a reputation, however.

I'm using Rotella T diesel motor oil in my new Yamaha 150 hp outboard, but will be switching to Mobil 1 after it gets broken in well. Rings just don't seat too well with extra slick synthetics.

 

[aerobat]

Re: Is Mobil 1 10w-40 ok in my engine?

however I have used this Rotella T 5w40 synthetic in link below in my motorbike which also calles for 10w40, cbr1100xx and it has been excellent and highly reviewed, can not really see an issue using it in a boat motor??...
http://www.bluewaveenergy.ca/LinkClick.aspx?fileticket=k7Cb9r_BkR8=&tabid=259

LOL -did you experience clutch slipping on your honda super blackbird? if not keep on going and you will experience soon. bikes have wet clutches which run in oil so need special oils designed for it. automotive oils will ruin your clutch quickly.
Motorcycle oil - Wikipedia, the free encyclopedia

back to boats : i run 10W-40 with no issues

 

[ciscokidd]

Re: Is Mobil 1 10w-40 ok in my engine?

LOL -did you experience clutch slipping on your honda super blackbird? if not keep on going and you will experience soon. bikes have wet clutches which run in oil so need special oils designed for it. automotive oils will ruin your clutch quickly.
Motorcycle oil - Wikipedia, the free encyclopedia

back to boats : i run 10W-40 with no issues

Dont want to sidetrack this thread but you have no clue about the 5w40 T6 full synthetic i am running in my cbrxx. I have 60000+ miles on the bike, this oil has been run n the bike since it had 5000 miles on it. Go read over at cbrxx.com, this rotella synth meets all requirements for wet clutches. I last replaced cluth plates when i had 45k miles on it. Current clutch is solid,the bike is not your average xx, it has undergone some major mods incl an entire 2011 Busa front end amonst other stuff. In the bike community Alot run Rotella T6 5w40 synth without issue


Back to boat. I am running Rotella T 15w40 triple protection, recommended by several marine shops that are Volvo dealers.