What oil?

[UMrk]

I just bought a 1995 Chevy K1500 Silverado with a 5.7 350. It has 180,000 miles on it, been maintained well. Going to be doing an oil change on it here soon, and not sure what oil I am going to use. The guy I got it from said he had been using 10w30, and said he wouldn't use a synthetic oil. I was going to use 10w30, but I don't know what brand to go with. I was thinking Mobil Super High Mileage conventional or the Castrol GTX but I cant remember if that is a synthetic blend or not. Anyways, thought I would ask. I live in Michigan if that helps at all.

 

[46Harry]

I believe a high mileage oil in a 10w30 grade would be good for your engine. Quaker State Defy, Pennzoil high mileage and Valvoline are good oils. I know the Quaker State and the Pennzoil are semi synthetic oils, I don't know about the Mobil or Castrol oils, though any of those oils will be good for your engine.

 

[addyguy]

I would use a 5w30 high-mileage oil.
Almost all are syn-blends now, so just go with which one you like the best.

 

[Falken]

Pennzoil High Mileage Vehicle.

Then as soon as the oil is changed, keep and eye out for sales on HM engine oil.

 

[skellyman]

Welcome to the forum ,
Any good quality 10w30 will serve you well, personal choice an price are often the driving factor .

 

[volk06]

Originally Posted By: UMrk
I just bought a 1995 Chevy K1500 Silverado with a 5.7 350. It has 180,000 miles on it, been maintained well. Going to be doing an oil change on it here soon, and not sure what oil I am going to use. The guy I got it from said he had been using 10w30, and said he wouldn't use a synthetic oil. I was going to use 10w30, but I don't know what brand to go with. I was thinking Mobil Super High Mileage conventional or the Castrol GTX but I cant remember if that is a synthetic blend or not. Anyways, thought I would ask. I live in Michigan if that helps at all.


Mobil Super HM is a great choice. Its also a blend not a conventional.

 

[salv]

Mobil Super HM is great stuff. I have run it in my XJ. Smoothest and quietest running of everything I have run. Peak ran great also.

 

[Greg L]

In my 1996 GMC truck with 189,000 miles, I have been using Valvoline Maxlife or Pennzoil High Milage. Both in 5w30 weights.

They have worked very well...and for some reason the Maxlife seems to run smoother (don't know why).


I have used Castrol High Milage in the past on this motor & it was fine, BUT it seemed to produce a pungent odor out of the exhaust versus the Valvoline And Pennzoil.


Just my experience with the 350 Vortec motor over the years of owning it.


GL

p.s. I have been told by others that using 10w30 will be fine also, and actually is supposed to be quieter in summer months.

 

[UMrk]

Thanks everyone

 

[artificialist]

Valvoline Maxlife is a syn blend, except for a few variants. It works extremely well in higher mileage engine, that is what I would recommend first.

 

[UMrk]

Hey everybody, I wanted to add to my original questions..... I noticed some oil on the bottom of my oil pan, have to investigate further but I suspect oil pan gasket or rear main seal. Anyways, my question about which oil to use in this truck has now got me thinking if I should stay away from the High Mileage oil, since they are synthetic blends?

I was going to go with either the Valvoline Maxlife or Mobil Super High Mileage, but with both being a synthetic blend and reading all about synthetic oil making leaks worse, I am now questioning what way to go. It seems the high mileage oil would be good to help clean the motor up a bit and also help with seals, but will the "synthetic blend" hurt my situation rather than help?

Thanks

 

[killswitch83]

Depends really. If this is a vehicle you plan on keeping, I personally will tow the line a bit and say to fix the leak, and go synthetic if you're looking to extend your OCI. Personally I use Quaker State Ultimate Durability 10w30 in my 99 Ram 5.9, and I've gotten pretty good results for an engine with 222K on the odo (basically going through about 1/2 to 3/4 a quart in 3K, and without topping off, the oil still looks its original amber color after said interval as well). IMHO, I wouldn't make an oil choice based on having a leak, just my 2-cents.......

 

[Clevy]

Forget the stigma of synthetics causing leaks. A synthetic high mileage is made for engines just like yours. High miles,old seals. The High Mileage oil will condition the seals preventing leaks.
Now if you've got a valve cover leak fix it. They are easy in that truck. Rear main seal not quite so easy.
There is a product made by a company called lubro-moly called "motor oil saver". It can be found at napa. Every leaker I've put this stuff in stopped leaking.
I've got 30 employees,most of them drive cars that are already 1 fender into the crusher. I've used this stuff countless times over the past few years in the staffs engines and unless the gasket is completely missing or broken this stuff fixes it.
5 bucks a can. Now if you have no leaks now then pick your favourite synthetic and a can of motor oil saver from napa and I guarantee no leaks.
If you get a leak using this stuff I'll pay for your next oil change with high mileage oil. I need pics of you pouring it into your engine. Make a vid with your smart phone and email it to me.

 

[fpracha]

I would take the offer by Clevy, unless I know some other mechanical problems exist in this truck.

 

[Jameson]

I am in the same situation with a tiny leak on my 2002 f350 5.4l v8.

I just picked up some mobil super HM to see if I can get it to stop seeping (no drip it just is wet). No oil loss over 6k miles almost. Just don't like leaks!

Maybe I will run to napa and add a bottle of this oil additive to see if it will help.

JC

 

[UMrk]

Thanks, I will stick with my original plan. Only leak I know of is either the pan gasket or rear main seal. Has brand new valve cover gaskets and no leaks there. I will look into that stuff.