What type of oil to use

[Martin]

I use to work at a lube shop. Castrol gtx is the only oil I'll use. I've seen first hand what other oils can do to a motor. Our manager had pictures of his truck with 350,000 miles on it. At 180K he rebuilt the top end, the heads were completely gunked up. All he had used was pennzoil. After the rebuild he switch to castrol, at 300k he tore apart he motor again and it looked brand new. Moble 1 and other synthetics are great but if you don't want to spend the extra money on them use castrol gtx.

[RChevy.48]

I am sorry, but it is just hard to beleive to me that there is only one conventional engine oil out there that doesn't put any build up on the heads, since all conventional engine oil is made from perefinic oil. I agree with hitman that if you change your oil regularly you will prevent sludge. I know everyone is going to come back with "I am in the business, so I know." I just think that if Pennzoil and Quaker State were the only two that put build up and sludge in an engine that they would be out of business. I am going to pull my valve covers in a couple of weeks and check to see what my heads look like.

[RedHeartbeat]

If you do a little research you will find that the crude oil that is pulled from the earth in the northern united states and canada is very high in paraffin. That is the oil that Pennz and Qstate use in their refineries in addition to foreign oils. You cannot remove paraffin from oil without very expensive processes so they left it in the refined motor oils. I remember a few years ago they both had big ad campaigns saying they reformulated their oil but that was long after they stunk up my opinion of their oil.
BTW, nobody said they are the only one that doesn't leave build up. They are just the two that I know that used to gunk up motors I owned and worked on for others.

[WHT6.0HD]

So, in your opinion and research does it show that the synthetic oil is a better product to use. I know in the past I have achieved over 200K mile on the castrol oil.

Now I only use synthetic and usually will keep a truck for at least 200K. Think I can make that on synthetic?

[RedHeartbeat]

Personally, I work for an oil company and I would prefer you use conventional motor oil instead of synthetic but that choice is for you to make. Synthetics are excellent products and I would not discount their claim to reduced friction and improved performance. In my own personal experiences I have found no true inprovement in fuel mileage. I have never run a new vehicle on synthetics oils and torn into after many miles. i did buy my current LS1 engine used and it was pretty clean on the inside though it had some dark deposits on the aluminum. The cylinders were is good shape though it had spun rod bearings. I don't know the history of the engine other than it was a dealership take-out. No history of type of oil used in this motor or if it was sythetics. I hear constantly of LS1s biting the dust due to spun rod bearings. Many believe a ported oil pump will prevent this from happening but I am waiting to try the pump from the new design variable displacement LH6 which is a much larger capacity pump.

[042500HD]

I use mobil1 and couldnt be happier

[JayBo]

MINE SPUN A BEARING , or more like 4..last month.. I had to replace the engine. I've used Chevron 5.30 ever since I've owned it, b/c I get it where I used to work and the whole service isn't but $20...Anyones opinion on Chevron oil?

[2k5Squirrel]

mobile 1 here.

[csherma1]

M1 for me in everything I own
I worked in several garges and dealers
I have seen first hand terrible things with Quaker and Penz
I have had great success with GTX in the past

[8budfan]

castrol syntec here...can tell a diff between it and conventional oil...specially in my big truck..