Mobil 1 synthetic oil

[vacaisle]

I'm pretty convinced that switching to synthetic oil is the way to go (for me). I tried Castrol GTX 20W-50 but there was too much lifter noise on start up and the pressure seemed a little too high, like the truck was working too hard to move the oil around once it was warm. Now I've got Castrol GTX 10W-40 in it and it runs pretty great. All winter I've been thinking I want to move to Rotella 15W-40 for the summer but the more I think about it the only differences are a heavier cold start viscosity (which I don't think I want because of lifter noise with 20w-50) and added ZDDP (which I want). The ZDDP lead me to Mobil 1. There's a lot of great info on here about Mobil 1 synthetic oils but not a lot of people say what viscosity they're using. I would think a lower cold start viscosity and a higher hot viscosity would be good in general. I'm thinking Mobil 1 high milage 10W-40 for the coming summer months here in NYC. Or would a lower cold viscosity be better like 5W-40? They both have about the same ZDDP levels according to this chart. Or should I try 10W-30 or 5W-30? I'm suffering from too much information syndrome.
What would you recommend oh great IFSJA.org?

Matt

[PlasticBoob]

How many miles on it? If your engine is in decent shape, I would use what the manufacturers recommend. For me it's 10w-30, even in our summers which routinely get into the 90s. On a higher-mileage engine 10w-40 is probably the way to go, or if you're going to be routinely driving in really warm temps (95*+ every day). I can honestly say I noticed a performance hit switching from 10w-30 (Mobil 1) to 10w-40 (Castrol Syntec) when I was experimenting with different oils early on. I used Bulltear's AMC dino oil to break in my new camshaft - talk about THICK! Geez, the Jeep felt like a tractor, lol. No camshaft troubles, though!

IIRC there is a chart in your owner's manual, or you can google it:

[PlasticBoob]

BTW, last time I checked, Mobil-1 barely had adequate levels of ZDDP for my liking - so I still add ZDDP with every oil change. I actually dug pretty deep into the Mobil oil reports and found the ZDDP level (in PPM) for Mobil-1, and it was slightly below the threshold that the "experts" were saying was required for proper flat-tappet camshaft operation.

Of course this all may have changed as my last research into it was at least four years ago, if not longer...that's why I am hesitant to actually spout off the numbers.

[KJ Ryu]

All I use now is Mobil1 high mileage 10w40. Used to use the extended performance 5w30 in my KJ on 5000mile changes but, it's gone now. Ran perfectly all the way up onto the wrecker though.

[Carnuck]

Amsoil doesn't need the ZDDP to lube as it's real synthetic. Mind you, I run NAPA synthetic 15W50 in mine with no probs.

[bwwhaler]

I have run mobil 1 10w30 in mine since I bought it from PO. Seems to do a good job.

[addicted]

Amsoil doesn't need the ZDDP to lube as it's real synthetic. Mind you, I run NAPA synthetic 15W50 in mine with no probs.

Real synthetic has nothing to do with it. If it did they wouldn't offer their high Zinc, Z-Rod and Premium Protection oils for older flat tappet engines.

[The PIG Smith]

All I use now is Mobil1 high mileage 10w40. Used to use the extended performance 5w30 in my KJ on 5000mile changes but, it's gone now. Ran perfectly all the way up onto the wrecker though.

I also use Mobil 1 High Mileage, but in 5W30
My WJ has 194K miles and it's 4.0 runs strong.
I use Mobil 1 in everything I own.

...with NAPA Gold Filters

[addicted]

I also use Mobil 1 High Mileage, but in 5W30
My WJ has 194K miles and it's 4.0 runs strong.
I use Mobil 1 in everything I own.

...with NAPA Gold Filters

I used Mobil 1 in my old 4.0 powered WJ from 6k ish to 130K ish and when I put the lifters and cam in it at 183K I could still see all the hone marks and the bearings looked almost new. I switched over to Amsoil around 130K because at the time I could get a years supply, plus filters delivered to my house for cheaper than anybody else's synthetic bought at a store. Now it is about the same cost with shipping costing so much. I am a firm believer in synthetic oil whether it comes from "real synthetic stocks" or the other versions that have been developed in recent years. Like Mobil 1 or my old stand by Valvoline.

[men in black]

I run Mobile 1 in all my vehicles and Gravely tractor

[SC/397]

I don't use NAPA/Wix oil filters any more. They must have changed suppliers or something because the anti-drain back valve doesn't work as well as it used to. I use a Baldwin B9 or B39 or the ACDelco PF24.

[vacaisle]

I'm going to go with Mobil 1 high mileage 10w-30 and see what happens. If it's weird I'll move up to 10w-40. Both of those have around 1100ppm ZDDP. Just out of curiosity has anyone run 5w-xx in a 360? I wonder if the lower cold start viscosity would be good in the winter?

[SJTD]

Maybe Mobil1 TDT has more ZDDP since it's for Diesels.

[PlasticBoob]

This might be incomplete, but a really quick Google search shows that the "magic number" for the minimum amount of ZDDP is 1200ppm. Some people are saying 1000-1250. Back in the day, the oils used to have 1400+ ppm.

I guess things haven't changed - personally, I wouldn't feel comfortable enough with only 1100ppm, and that's why I add it. IIRC it does deplete over time, and I don't think adding just a bit more is going to hurt anything.

[svining]

Mobil 1

I am running Mobil 1 10/40 now, I thought it was a little thick for the winter especially cold starts with my turned down idle RPM. I am going to change to 5/30 extra milage, not to be confused with their high milage oil, next change which will be at the end of the summer.

I did get a little tappet noise on start up and slow build up of pressure on cold mornings. She is very happy on it after circulating the oil. At 135,000 miles runs at 40lbs all the time.

This might be incomplete, but a really quick Google search shows that the "magic number" for the minimum amount of ZDDP is 1200ppm. Some people are saying 1000-1250. Back in the day, the oils used to have 1400+ ppm.

I guess things haven't changed - personally, I wouldn't feel comfortable enough with only 1100ppm, and that's why I add it. IIRC it does deplete over time, and I don't think adding just a bit more is going to hurt anything.