Pennzoil conventional oil still available

[Carlostrece]

I didn't think any company still offered conventional motor oil, but fun fact.. Tonight I noticed on Pennzoil website that Pennzoil still offers a conventional oil in a few viscosities.

 

[MurkyAsparagus]

The good ol’ yellow labeled bottle.

There’s a few other companies that still make conventional oil like Castrol, Chevron, Shell, and Valvoline to name a few. It’s becoming harder and harder to find.

 

[Lubener]

I do not have any problems finding "conventional" SP rated oil in my area. I don't believe there is a 100% conventional around anymore. I wait for a deal since there is a narrow price gap between conventional and synthetic. I prefer to use conventional in my old vehicles and will continue to use it till its gone forever..

 

[Snagglefoot]

At our Walmart ( in Canada) the difference between the “ conventional “ 5w30 Super Tech and Full Synthetic Super Tech is $2.80 U.S. equivalent per 5 liter jug.

 

[eljefino]

We've pondered here that the PZ conventional often winds up with surplus synthetic base stock and isn't advertised as such.

Sucks for people like Mazda rotary owners who have to use conventional.

 

[Carlostrece]

The good ol’ yellow labeled bottle.

There’s a few other companies that still make conventional oil like Castrol, Chevron, Shell, and Valvoline to name a few. It’s becoming harder and harder to find.

The only Chevron oil I've seen in last 20 years said ISOSYN on the bottle, which an Oreilly store manager told me is Chevron's brand trademark name for synthetic blend. Am I missing something?

 

[SC Maintenance]

Most 10W-40 is still conventional. I just bought some Havoline. Posted about it here.

10W-30 is also still available as a conventional.

 

[Carlostrece]

Back in the day, before Valvoline invented HM oil by creating Maxlife...

The original go-to for an old engine that leaked oil, or a worn engine that burned oil, was to use a thicker conventional oil.

A slightly thicker brand of conventional that was still within grade was usually effective for an old engine still in marginal condition.

A thicker grade conventional was the most effective option for a very old leaker, or heavily worn oil burner.

HM oil didn't exist back then, but we still had ways to help old engines.

Modern HM oils offer an improvement in base oils and additives, which is great. However, I still think there's no subsitute for viscosity.

Another thing... All the old timers I knew in the 80s & 90s who had been middle age in the 60s & 70s said synthetic leaks and burns more than conventional of the same viscosity. My autoshop instructor was one of those old timers.

I didn't necessarily believe them at the time, but then my life experiences with several cars over 40 years showed me that they were correct.

So for a very leaky or oil burning car I'd ideally rather have a conventional HM oil (if one existed). My 2nd choice would be a Blend HM oil.

I think synthetic HM oils are great for HM cars that are in OK condition (don't leak or burn much), but for a very old or very worn out car it's been my experience that synthetic HM leaks more than a Blend HM of same viscosity.

IME a conventional non-HM won't leak or burn anymore than a HM Blend of similar viscosity. Both of those leak less than a synthetic HM. At least that's been my experience with several cars over a few decades.

So perhaps there's still a few applications where conventional oils are preferrable. There's defineately still applications where they're acceptable. Also there's some applications where Blend is ideal.

 

[Snagglefoot]

Here are pictures of two different Pennzoil products. The first one is 5w30 with no other designation on whether is conventional or not. It’s rated as SP.

The second product is also 5w30 but is marked as synthetic blend. It’s also rated as SP.

There were discussions earlier on whether “ conventional” oil can meet SP specs without containing some semi-synthetic oil. Both photos were taken on the same day.

 

[Lawnman23]

Sucks for people like Mazda rotary owners who have to use conventional.

I know rotary’s are a world all unto their own and they are basically sci-fi to me but why do they require conventional?

 

[Carlostrece]

I know rotary’s are a world all unto their own and they are basically sci-fi to me but why do they require conventional?

You're asking why rotary engines need to use conventional motor oil and not synthetic. At first that seems counter intuitive because rotary engines often have high rpm.

I don't know for sure, but I'll venture a guess based partly on facts I know and partly my theories to fill in the gaps of what I don't know for sure. I've never owned a rotary.

I think it's because conv oil is better at sealing. i.e. - better compression due to less blowby in a loose engine. Also less oil consumption due to better sealing.

I said earlier in thread that conventional is less slippery than synthetic and less slippery is an advantage in some situations. For examples: Conv does less slipping past rings, seals and gaskets. Thus for worn or old piston engines conv does less oil burning and less leaking. Conv also has less blowby. (All this based on comparing same viscosity oils). Everything in this paragraph I know to be facts.

Rotary engines weakness is that it's difficult to get a good seal during combustion. i.e. - there's some blowby. Everything in this paragraph I know to be fact.

I theorize that conv oil would reduce blowby and oil burning in a rotary engine just like it does in a worn piston engine.

Rotary engine owners please let me know if I'm correct.

 

[ripcord]

The only Chevron oil I've seen in last 20 years said ISOSYN on the bottle, which an Oreilly store manager told me is Chevron's brand trademark name for synthetic blend. Am I missing something?

ISOSYN base stocks are what are known as Group II+. Somewhere close to Group III but not quite. Still pretty good stuff, though.

I don't know for sure, but I believe Chevron adds some Group III base stocks to it in SP rated oils.

 

[AZjeff]

I contacted Pennzoil and confirmed that the 10w-30 and 10W-30HM are conventional. Also the 10w-40. PYB 10w-30HM dries up a RMS seep in the Jeep. Supertech FS 10W-30HM made the seep come back in 1000 miles. Dumped the ST at 1500 and put the Pennzoil back in, almost dried up again.

 

[Carlostrece]

ISOSYN base stocks are what are known as Group II+. Somewhere close to Group III but not quite. Still pretty good stuff, though.

I gave Chevron conventional with ISOSYN 5w30 a chance, but it went through my old HM car like poo through a goose. Way to much oil burning, leaking, and oil loss. My car behaved like it was all clapped out, even though it's actually a good car.

I think Chevron runs too thin per grade for use in an old HM car. IME.

I had good results (with same car) using conventional 5w30 Mobil, U76, Shell, Valvoline, and Pennzoil oils. Mobil, Shell, and Pennzoil were the thickest 5w30s. Valvoline and U76 were adequate. Any of those work well in my HM car, IME.

 

[jkasch]

Back when I first registered as a member here, it seemed like whenever someone asked about what to do about an engine that had been neglected with regard to oil changes, the stock response was to do several short OCI’s with PYB. As if it had extraordinary cleaning abilities. Times certainly have changed.

 

[eljefino]

Here are pictures of two different Pennzoil products. The first one is 5w30 with no other designation on whether is conventional or not. It’s rated as SP.

The second product is also 5w30 but is marked as synthetic blend. It’s also rated as SP.

There were discussions earlier on whether “ conventional” oil can meet SP specs without containing some semi-synthetic oil. Both photos were taken on the same day.

Remember marketing loves "good, better, best." Why do we still have midgrade gasoline when virtually no modern cars take it? Because people buy it.

If people pay extra for "syn blend" when the conventional can be considered a syn blend, why would Pennzoil disavow this opportunity?

 

[Carlostrece]

I contacted Pennzoil and confirmed that the 10w-30 and 10W-30HM are conventional. Also the 10w-40. PYB 10w-30HM dries up a RMS seep in the Jeep. Supertech FS 10W-30HM made the seep come back in 1000 miles. Dumped the ST at 1500 and put the Pennzoil back in, almost dried up again.

A conventional HM oil should be the ultimate leak stopper because it'd have the advantage of conventional oil does less leaking, and HM additives also reduce leaks. So with a conventional HM you're getting both advantages for reducing leaks, oil burning, and blowby.

If the oil also runs on the thick end of grade at KV100, that's an additional reducer of leaks.

A person could even take that a step further and go up a grade, if it wouldn't be too thick for the engine. However, I would only do that on a very clapped out engine that's on it's last legs.

 

[Carlostrece]

If anyone is interested and willing, it'd be interesting and useful if we had 3 lists of what's available in 2025 for:

Conventional oils
Conventional HM oils
syn Blend HM oils

I'm especially interested in Conv HM oils and Blend HM oils because IME conv is least likely to leak, burn oil, or have blowby; and Blend is less likely (than full syn) to have those problems. Also, conv & blend cost less than syn.

I also like blend because while it offers some of the leak reduction of conv, blend also offers some of the lubrication benefits of syn. Blend is a good jack of all trades oil, especially a HM blend.

I'll start the syn Blend HM oils with my favorite 5w30 HM blend oils for reducing blowby and reducing leaks:
Valvoline Maxlife Blend Plus (black bottle) 65, 11 (10.9 IRL)
Quaker State HM Blend 68.4, 11.1 (11.4 likely)
Valvoline Maxlife Blend (red bottle) 65, 11 (10.9 IRL)
Pennzoil HM Blend 70, 11.7

The viscosity figures above are cSt @ KV100 taken from data sheets.

In parentisis the IRL viscosity is from VOAs from oil labs (not Blackstone).

In parentisis the likely viscosity is my guess based on VOAs from oil labs (not Blackstone) on other similar oils by same brand.

Mobil Super HM (blend?) 63, 10.3 might be a blend. It might be full synthetic. I'm not sure.

 

[AZjeff]

If people pay extra for "syn blend" when the conventional can be considered a syn blend, why would Pennzoil disavow this opportunity?

That doesn’t explain why 10W-30 and 10W-40 don’t say syn blend on the bottle but 5W-30 does. Might it be true?

 

[Snagglefoot]

That doesn’t explain why 10W-30 and 10W-40 don’t say syn blend on the bottle but 5W-30 does. Might it be true?

Of course posting 9 shows a 5w30 synthetic blend and a 5w30 with nothing noted.