Oil for a 160,000 mile engine


BrunoPizz97

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Need suggestions as to which oil to use
Ive used Rotella 10-30 diesel oil it was great but i feel like I need something with more zinc in it to protect those moving parts.
 

strumble8

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Shell rotella is one of the few oils that still have zinc. Valvoline high mileage synthetic blend is another. You could always use a zinc additive like zmax. (Full disclosure I have never used it)
 

Mr. Bills

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You don't really need an oil with "extra" zinc. Motor oil formulation has come a long way since the flat tappet/leaded fuel era.

Any of the "high mileage" conventional or synthetic motor oils should be fine. Since you like Rotella, there is new version specifically for gasoline engines.

I use Valvoline "Max Life" synthetic blend because it has worked well for me in the past and I have found no reason to change brands just for the sake of change.
 
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BrunoPizz97

BrunoPizz97

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You don't really need an oil with "extra" zinc. Motor oil formulation has come a long way since the flat tappet days.

Any of the "high mileage" conventional or synthetic motor oils should be fine. Since you like Rotella, there is new version specifically for gasoline engines.

I use Valvoline "Max Life" synthetic blend because it has worked well for me in the past and I have found no reason to change brands just for the sake of change.
ok I like this response not bad.
 

CodaMan

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I use this high mileage conventional. It also stopped my small RMS leak.

mob-120774_uj_xl.jpg
 

freedom_in_4low

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What you're looking for with zinc is anti-wear film strength, specifically between the cam and flat tappet lifters. This is basically how much pressure it takes to completely squeeze the oil out between two surfaces and cause metal-to-metal contact. Zinc was a popular way to get it, but they've found other ways to do it over time.

Rotella and many other diesel oils, even if they have zinc, generally have terrible film strength. The report I read put Rotella T6 at 67k psi, vs most name brand gasoline engine oils were at least 90k and some were up to 120k.

There are enough 300k+ mile 4.0s out there driven by owners who didn't give two craps about zinc content to support the argument that it doesn't even matter on a 4.0. If you're blasting through Baja or running around Laguna Seca or ripping down the 1/4 mile in the types of engines one would use in those applications, it probably matters. This probably explains why they don't work so hard to get film strength in diesel oils...they're turning so slowly it's just not important. The areas a diesel engine sees more load is in the crank and main bearings, where the oil layer is provided by oil being pressure-fed into the bearings faster than it can escape and film strength doesn't matter. They care more about the detergents in the additive package.

My last oil change (Saturday) I put in Valvoline Full Synthetic with MaxLife technology because it was one of the highest in film strength, but it's not going to stay because it also dramatically worsened my lifter tap (consistent now with 2 different Valvoline products). I'll try Pennzoil High Mileage next but if it isn't better than Castrol GTX High Mileage then I'll go back to the GTX and stick with it.
 
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Jerry Bransford

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NO, the 4.0L engine's design does not need more zinc than is already present in common good quality engine oils like from Valvoline, Mobil, Castrol, etc.. You need extra zinc for high compression engines with stiff valve springs that cause extra wear on the cam but that's it.

For a high mileage engine like yours Mobil Super 10W-30, a high-mileage design with extra seal conditioning additives, would be very (!) hard to beat.

What keeps our engines running well is nothing more than regular oil and filter changes, not overpriced engine oils like from Amsoil, Royal Purple, etc.

In 50+ years of driving, I have NEVER not once had an engine problem yet I run nothing but conventional engine oils from Valvoline, Mobil, Castrol, etc. And most of my engines are near 200k miles old by the time I get rid of them. My previous TJ had 192k miles on it the last time I saw it, never anything but Valvoline 10W-30 conventional, and its engine was still running like the proverbial top.
 
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BrunoPizz97

BrunoPizz97

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NO, the 4.0L engine's design does not need more zinc than is already present in common good quality engine oils like from Valvoline, Mobil, Castrol, etc.. You need extra zinc for high compression engines with stiff valve springs that cause extra wear on the cam but that's it.

For a high mileage engine like yours Mobil Super 10W-30, a high-mileage design with extra seal conditioning additives, would be very (!) hard to beat.

What keeps our engines running well is nothing more than regular oil and filter changes, not overpriced engine oils like from Amsoil, Royal Purple, etc.

In 50+ years of driving, I have NEVER not once had an engine problem yet I run nothing but conventional engine oils from Valvoline, Mobil, Castrol, etc. And most of my engines were near 200k miles old by the time I get rid of them. My previous TJ had 192k miles on it the last time I saw it, never anything but Valvoline 10W-30 conventional, and its engine was still running like the proverbial top.
ordered valvoline
 
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