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Yeah it’s way past break in period haha. I’ve also heard as the engine gets older it’s common practice to use a heavier weight oil.
It depends on a few factors.
1. Oil viscosity, in an otherwise good condition engine, is chosen by the engineers based largely on the LOAD that the bearings will see. High specific output engines - turbocharged, and supercharged, etc - tend to specify heavier oils to prevent the oil film from being compromised due to the forces involved in high cylinder pressure applications. You can see this in such examples as the BMW M-series vehicles which specify 10w60 from the factory, and the recent Ford Focus RS with a 350 HP 4 cylinder that specifies 5w50 from the factory. Neither of these engines have significant differences in the machined tolerances inside the engine - they need the viscosity to prevent the oil from being squished out of the bearings. The clearances used are largely the same as the age-old rules that most engine builders would be familiar with. About a thou per inch of journal diameter.
2. Sometimes in worn engines, heavier oil can improve marginal oil pressure. This is ultimately a band aid but can buy you some time.
If your oil pressure is normal, and you aren't running a highly tuned engine at high RPM or with turbo/supercharging, you are almost certainly best served by something not so exotic like a run of the mill synthetic 30 weight (5w or 10w - which ever you feel like depending on season). There is zero reason to run non-synthetic at this point. The stuff is cheap and has significant advantages long term. Added with the longer change intervals it's pretty much a wash in terms of cost so it's a no-brainer to do the job less often, get better results, and spend the same amount of money.
10W30 is perfectly fine, Ben. An older engine may or may not benefit from a heavier oil, but going from 5W30 to 10W30, neither you, and especially not your engine, will notice a difference.
As for the aforementioned zinc/phosphorous, today's oils(since 1994) are low in z/p. So all 3rdgen engines were high on z/p until 1994. Good for engines, cams and lifters, but not so good for catalytic converters, which is why the z/p content was lowered. So for the last 26 years, unless people needed, or wanted, high z/p oils and additives, and most probably have not, then everyone has been using low z/p oils, probably without realizing any such change had occurred.
86 and earlier engines, flat tappet cams/lifters, and "built" engines, will benefit from high z/p. 87 and newer roller engines will, too, but low z/p is fine for them, and obviously has been for 26 years, just as it is for new engines.
I've used 20W50 in my Formula for over 30 years. But I live in the desert where winters are brief and mild, and the rest of the time it's hot af. 1 of the 5 quarts has always been Valvoline VR1 Racing 20W50, which contains high z/p. And until 2001, the other 4 quarts were the "brand of the month." But since 2001, the other 4 quarts have been Valvoline Max Life.
High mileage oils are for real, good for new vehicles too, and especially good for SBCs. I've used VML in all of my new vehicles since their first oil change, and I put obscene mileage on all of them. VML began as a conventional, then became a blend, and now is a full synthetic. The Formula gets 4 quarts Max Life 20W50 + 1 quart VR1 20W50, and my other vehicles get their recommended weights.
Things people shouldn't sweat: extreme intervals between oil changes; mixing or changing brands; mixing or changing weights. If anyone ever finds him/herself in a "situation," oil is oil, so just put in whatever is available at the moment, and all will be well; the engine won't care. So a change from 5W30 to 10W30? That's nothing to worry about, hardly a change.
yes but is it high in zink new oils may mess up motor.
This just isn't true. Newer oils are backwards compatible because the specs for purity, lubricity, detergents, and performance continue to increase. Our cars are old now, but even back to the 60s, those motors run on current oil as well. With better oils and better filters, we now extend the life of oil to longer intervals, even with tighter tolerances in today's engine. "Meets or Exceeds" is what is in most owners manuals, including my lawn mower.
As for the zinc, not only did it hurt catalytic converters, but also contributed to buildup inside the engine.
Instead of Zinc, they now use Boron. The exchange is some cold start protection. This will not "mess up" a motor. May contribute to wear over an extended period of time, but other issues will come into play before that occurs. They do have additives you can run with each oil change to help with this.
Rotella has Zinc in it already. Use it and you wont have to put in an additive.
True, but if you are not cat-less, you may get another repair bill as well. There are better additives today that can be used to provide the same protection without Zinc. I would suggest using one of those instead of a Zinc additive or oil with Zinc in it.
Rotella has Zinc in it already. Use it and you wont have to put in an additive.
Not so. That was true at one time, but Rotella has reduced levels of ZDDP since modern diesels now have catalytic converters.
Additionally, the reduction in ZDDP from modern motor oils took it back to the levels that motor oils had in the 1960s. It still has it, just not as much as it did at one time. The only time higher levels are really necessary is during a new flat-tappet cam break-in, or if you run a performance cam with stiff valve springs...
