Which synthetic is the very best?

[Jimamatic]

I know this has been hashed over many times, but I'm thinking of finally making the switch to synthetic. I've been using Rotella T 15w-40 and have narrowed it down to either Rotella T 5w-40 or Mobil 1 5w-40. Price is not a factor. I want the best and I'm willing to pay for it. I do know that mobil is a group 4 vs Shells group 3 base stock, but does this make Mobil all that superier? I know the additive packages make the oil more than just the base stock. What are your thoughts?

Jim

[cme4lyt]

Amsoil...no question...simply the best your truck can have...

[KenZ]

Hi Jim,

I've always used amsoil for about the past 30 years in all my vehicles. However, I wasn't pleased with some of my oil test results on my truck. I switched around a little and tried a couple of the amsoil diesel oils and the Shell Rot. 5w40 Synthetic. I consistently got better test results--lower comtaminates with the Shell than the Amsoil. Can't tell you why, but it just seems the truck likes the Shell better.

Ken

[mcmonroe]

Mobil Delvac 1

[Driveshaft]

DITTO, MARK MONROE.

[JD Diesel]

Amsoil have been running it for twenty years. And have seen it stand up to things the other oils would just cry if they had to go there . And not just because I sell it. That's my humble opinon. JD

[Tough Guy]

If price is no object then get Mobil Delvac 1...

If you want the best for the money then get the Rotella 5w-40. I use it both my Diesel trucks and really like it.

Chris

[Jimamatic]

Thanks for the replies. Well, I thought price was no object until I priced a case (4 gal) of Mobile Delvac 5w-40. $105.00 holy cr#p!!! I still have not decided but Rotella T is looking alot better, considering quality vs price. Thanks for your opinions....

Jim

[JD Diesel]

4 gal amsoil is 90.25 add a dual remote bypass filter. and do oil anialise every 10,000 miles they will even tell you when you need to change the filters. JD

[jbplock]

Also consider 5w40 Mobil-1 Truck and SUV - same as Delvac-1.... $3.74 per qt at my local Wal-Mart.

(M1 T&SUV is API certified for CI-4, D1 is CI-4+)

See Engine Oil for more info..

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[LanduytG]

Best buy on a top quality group 4 oil is the Amsoil AME 15W-40 in the 5 gallon case. Thats 2 10 quart jugs then add the new EAO52 oil filter and you have the best. Oil is $80 ($4 a quart) for the case and the filters are $13. So you get 2 oil changes for $106. You can run at least 15K without even breathing hard. IMHO anything over that and you need oil analysis.

Greg

[Jim Brzozowski]

One thing to consider is the warranty on the engine. If GM ever finds out from your records that you ran past the oil change intervals they recommend they could deny you warranty work on the engine for the first 100k. Just a thought, of course on the other side of the coin, if you use the best oil your chances of having a problem with the engine is much less. I suggest you use the best you can afford based on the need to perform under the conditions you expect it to. Only you know what you're gonna put your engine through.

[Black95TD]

What do you guys think about using Shell 5W-40 synthetic for one change Dec thru Feb. or so for easier starting , better cold lubrication, better milage etc and using Shell 15W-40 the rest of the year. It can get down to near 0 frequently here in northern Connecticut during Jan. The popular belief is that once you switch you should continue on forever. I like to change the oil and filter every 5K on my new LLY. Used to do 3K with the old 95 but the new motor doesn't seem to make the oil so black plus there is 10 qts. All the synthetics say they are fully compatible.

Anyone had good luck with this approach?

[Carbon D/A]

The Mobile truck and suv synthic at wally world comes in a 5 quart container for about $21.00. i use this oil in everthing, lawn tractor, truck,4 stroke dirt bike, generators... I dont know why but i BELIEVE, Its got to be good for this price ?

[JD Diesel]

Have had a dealer try not to take care of a warrent issue. slapped down my oil analise issue was no longer a problem. JD

[FrankA]

my local lube and oil change place just got the
5w40 Mobil-1 for the diesel in but he said mobil aslo mskes an oil filter for the Duramax. Anyone here anything about a mobil oil filter and should I use it?
thanks
frank

[Jim Brzozowski]

JD DIESEL, that sir is good information everyone needs to know and your right. They can't argue with the oil analysis.

As far as changing weights for winter to summer. I really doubt it makes a difference. I run the 5W-40 year round. One thing thats not too well known it that the Champ turbo cars that used to run at Indy before the IRL took over, they ran 0W-30 in those engines. I haven't talked to any of the car owners in IRL so I don't personally know what they run now, but they aren't turbo engines.
My opinion is that the faster the oil flows through the system when you first hit the starter the better it is for the engine i.e. I use the 5W-xx oil in everything I own including lawn mowers. I've never worn out an engine. Something else always happens to make me want to get a new one, but never because the engine was too worn out. Lubricants today are so, so much better than they were a few years ago. Compliments to everyone involved in Petroleum research and of course it doesn't hurt that NASCAR has adopted Mobil 1. I have no doubts that Amsoil is at the top of the list too. I use Shell for the value and My wife has worked for Shell for years as well as some of my old racing buddies who worked in the oil analysis testing labs at Shell, so I know what their quality is. It's good enough for my truck for the price. Red Line has always been a highly acclaimed oil and Royal Purple has really come on strong over the past few years. You've got to make your own decision. I assure you if it meets the specifications required for your engine and its any of the brands I've mentioned you can't go wrong.

[jbplock]

Originally posted by FrankA:
Anyone here anything about a mobil oil filter and should I use it?

Frank,

The Mobil-1 filter is an excellent choice.. For more info see Mobil-1 Filter for the Duramax, M1-303

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[LanduytG]

The M1 and the old Amsoil SDF where about the same. Now we have the new Amsoil EaO filters that are 15 micron at 98.7% for only $13, if ran with Amsoil oil its 25K miles or once a year. Of course I am sure that Delvac would run that as well.

Greg

[Jomar]

SoTexPollock,
Are you related to any of the Pollocks from Hargill ??