Best oil for 178k+ 4.0L v6

Hi everyone,

It's time for me to change the oil for my truck and I wanted to ask what you guys know about oil viscosity and high mileage engines. The previous owner ran 5w-30 Pennzoil conventional. After reading form Bobistheoilguy.com, I'm looking to put in 5w-30 Catrol GTX conventional. However, my mechanic has been pushing for me to switch to 10w-40 since it's high mileage.

I tried looking through other threads and forums but there doesn't seem to be a clear suggestion.
What do you guys with high mileage do?

Thanks

 

In my opinion, unless you truck is leaking or some other issue, stick with what is working 5w30 conventional. I have had a few Toyota's with 200k + and a 4Runner with 475k and I always used Toyota's recommendations for viscosity. I wonder why your mechanic is suggesting a 10w40...

 

Stick with 5w30. I prefer synthetic in my cold climate but whatever.

 

He is saying because it's an old truck I shouldn't take any risks and that it's worth having my mpg's dip downwards for superior engine protection. I've read that it's more common with 250k+ engines so I wasn't sure if it's worth it or not.

 

A heavier oil can wear down other things though. Toyota recommends it for a reason.

 

Hmm, that is true. I need to look into what these parts are and weigh the positive and negatives of either oil with engine reliability. Thanks!

 

Stick with the 5-30 I have over 250k on my 07 Tacoma 4.0 purrs like a kitten...

 

Are you running synthetic or conventional? High mileage vs standard? and which brand?

Thanks!

 

Mobil 1 synthetic extended drain toyota factory filters change about the 7500 mile mark...

 

Thanks!

 

bang3410 you are quite welcome...hope it helps.

 

ditto, mobil 1 or Ams if you got the mullah, I went mobil 1 two times ago, then found out about ams, I will go ams every time unless mobil 1 has a realllllly good deal at costco.

 

5W-30 works best, stick with what works.

 

I would stick with 5w-30 as well. Whether you go with conventional or synthetic is your choice. But personally, I would use a high mileage formula regardless. They contain seal and gasket conditioners.

 

Don't overthink it and make a simple decision difficult. Just use the oil that Toyota calls for.

 

It calls for 5w-30. Simple as that

 

Let me guess.

Your mechanic is in his 50's? Or if in his 30's or 40's is a second generation mechanic?

Stepping up viscosity was a common practice, as recently as the 70's and 80's to help counter things like ring wear. But at this point it's the continuation of a technique that is very dodo bird.

If a component has worn enough to cause compression loss or oil consumption, the only fix is to replace the offending part(s), assuming the required expense is worth it to save the vehicle. For example, if it runs well and consumption is 1qt every 1k miles, just check the oil and add more. Simple.

There's no value for you to change to syn at this point. Modern SN conventional oils are almost as good as syns of just 10 years ago. So I'd stick with the 5/30 the PO used, and not even worry too much about the brand. You might use a 'high mile' oil though, as their additive package is a bit different.

Just change it by a reasonable standard and use a decent filter.

PS, no dispersion on your mechanic, especially age. I'm well into retirement and have 8.5 grandkids. We all get set in our ways sometimes.

 

I love a good oil thread!

 

Dance with who brought you... If it worked this far, keep using it!!

 

The previous owner ran 5w-30 Pennzoil conventional and I was told to change to a different oil ASAP. I can't quite find a conventional high mileage 5w-30 oil to stick with besides Pennzoil High Mileage, which I was told to avoid by multiple people.

He's actually in his late 20's. He was my mechanic for my Subaru and works at a popular Subaru repair shop.