Want to switch from Rotella T 15w-40 to a full synthetic oil. Any ideas?

[Dr_Snooz]

Also, some people say that Mobil 1 is good for 10000 miles before needing to change.

I only use Mobil 1, but I change it when it turns black. That's usually around 5k. Any longer and you're just recirculating dirt through the engine. It's great oil, but it still gets dirty. All the German car makers are saying that the synthetic oils can go 10k and 15k between oil changes. You wonder if that's because they really can go that long, or because the automakers are paying for the first few years worth of oil changes now.

[Russ130]

I only suggested Mobil 1 because that is what a lot of customers insist on for their cars. Gotta admit though what other company has the resources to develope and constantly improve a product than Mobil. They hire the best scientists and chemists on the face of the earth and put them in the best labs equipped with all the best instruments. They also do more than oil and gas too.

[eventhorizon66]

Someday I'll switch to a synthetic (probably RP) at which point I'll run about a year between oil changes.  But I will change the filters twice a year.

If you are concerned about how long you can run between oil changes with synthetic, I'd run it for 3000-5000 miles and then send in a sample for analysis.

http://www.oaitesting.com/

[bobcooter]

If you plan on changing your oil every 3000 to 5000 miles a good conventional oil l will do fine. I personally like Valvoline. Synthetic is OK too but, you said your engine was recently rebuilt. I would not make the switch until I had well over 3000 miles on the rebuild. Also, some people say that Mobil 1 is good for 10000 miles before needing to change. That's what we were doing with out company trucks, then someone said something needing a special filter to go that far.  You need to check on this if you decide to go that route. My honest opinion is that if you are doing normal driving and you plan to do the maintenance on your truck yourself, synthetic is a waste of money.

Synthetics are the only oils that contain enough Zinc for a flat tappet cam engine.  If you have a roller, no, you do not need it but a flat tappet cam NEEDS to have the Zinc.  Why do you think all engines all rollers these days?  Oil can still be produced cheaply without potential engine failure.  Synthetic will not break down as easy, has lots of Zinc and is far superior to conventional oil.  You should research it yourself.  It's quite an interesting topic.  The only use conventional oil has is properly breaking in an engine.  After that, it's useless.

Nearly every small block chevy ever built has a flat tappet cam.

[grinder1989]

Nearly every small block chevy ever built has a flat tappet cam.

Except for every small block produced from 87-03.  Those were all roller cams.  Even the Vortec (last small block engine produced used in trucks) were roller cam.  I'm sure the cam in my engine is a roller.  That's why I'm not running synthetic in it.

[TexasRed]

Actually a lot of the truck motors were still flat tappet 87- up until prolly vortec. The blocks were ready for roller cams, just didn't have them.

[bobcooter]

Nearly every small block chevy ever built has a flat tappet cam.

Except for every small block produced from 87-03.  Those were all roller cams.  Even the Vortec (last small block engine produced used in trucks) were roller cam.  I'm sure the cam in my engine is a roller.  That's why I'm not running synthetic in it.

[VileZambonie]

What are you  about bobcooter?

[SUX2BU99]

I ran Rotella for a while but stopped because it isn't as available as regular oils like Castrol, Valvoline, etc. Although I say that and the local Walmart now carries it. I use conventional oil and a bottle of GM E.O.S. It's like a break-in supplement. I change my oil once in the spring though because my truck only seems summer use.

[bobcooter]

What are you   about bobcooter?

Nothing... I read Grinders post backwards...

[86silverado]

i run Brad Penn oil in mine, has higher zinc concentration its partial synthetic, everytime we have pulled valve covers to run valves, inside of motor looks as clean as it did when it was built.      website is http://www.bradpennracing.com

[Blue 82]

Mobil 1 oils have different levels of Zinc and Phosporus
The only one Mobil recommends for Flat tappet cams is 15W/50

Rotella or Delo for me.

 http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

[bowtieman82]

you can run what ever you want. they both protect good. as long as u change the oil regular. if you run a roller cam u don't have to run synthetic oil with. if u run regular oil with if it will be just fine just break it in they way the manufacture tells u. but u don't have to but if you want it run it.