Safe to mix Pennzoil PB with Mobil1?

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The only synth Id mix with pennzoil is the Pennzoil synthetic, and the only dino Id mix with Mobil 1 is mobil drive clean...
Even then, Id be a bit skeptical, as you cant be too sure that the additives will like each other when in the mix... I think its fairly safe, and if I wanted such a thing, Id do it in my car, but in generaql I think its best to do all dino or all synth, and stick with a single brand for at least a few oil changes...

No it will cause a reaction that will cause a nuclear bomb like blast All like oils are mixable example, sl oils or ci4 oils All the additives are basically the same it will not cause any problems in an engine.

[ March 23, 2003, 10:04 PM: Message edited by: Steve S ]
There won't be any problems, but probably not any benefit, either. You might not get the best protection that either oil used alone would offer.

Why mix oils? There's no real advantage, and anything you want to achieve can be gotten from the correct single product.

My uneducated two cents worth.

You probably get more bang for the buck mixing a quart of synthetic with three of dino vs. buying a blend that's only 10% syn.

Since Mobil 1 Drive Clean's a group I oil, Pennzoil is probably just as compatable with Mobil 1 as it is and probably a better oil for the money IMHO.

We're all getting carried away with this stuff anyway. I've owned approximately two dozen cars over the years, plus three bikes. Had exactly three engine failures for the lot. One was a Corvair (nuff said), the other two were Mitsubishi engines: one lost coolant and I cooked it, the other was the infamous Mitsu 3 liter V6 valve guide eater. Since the transmission was toast at 100K, it wasn't worth putting in valve guides. Many of the others went way over 100K with little if any worry. Most that died, went to the big reward for other causes than engine problems.

[ March 25, 2003, 03:16 PM: Message edited by: csandste ]
I'm actually running diff brand/weight now. Started with 3 quarts Castrol HM and 2 quarts regular Castrol GTX both 10w30 SL. Since the motor is consuming a little bit of oil, I've since topped it of with Pennz 15w40 LongLife CH-4/SJ 1 quart.

I wanted to run heavier oil to begin with to slow/eliminate the oil burning but the temp at the time of oil change was still too cold for the 15w40 dino.

For my next change, I'll use Penz LL 15w40 4 quarts and 1 quart Castrol GTX. If the consumption continues, then I'll just top of with Castrol. Why mix brand etc? Well, the Penz come in 1gal jug at WM for only $5.38 and I still have several quarts of the GTX and HM in the garage.

My truck got 137k, runs fine, gives me consistent MPG for my type of driving. Does mixing oil have bad effect? Dunno, I guess time will tell.
i want to see analysis of people mixing oils. i seen analysis that people had another kind of oil and then it interfeered with their analysis and none of them turned out bad. but i would only mix brands with brands. like mobil drive clean, and mobil drive clean blend. or mobil drive clean and tri synthetic. i dont know if there is any good to blending, u may be getting best of both worlds, or you are plain just not getting nothing.
When I had a Ford Taurus company car, I changed the oil every 7500 miles according to the book and added whatever oil I had in garage if it was low. This this included everything from Mobil 1 15W-50 from my VW to Pennzoil 30WT from my lawnmower. It was returned with 100K miles and ran great, everything electrical went to crap though. Due to the 100K tune-up intervals, I only changed the oil/filter @ 7500 miles, the fuel filter at 60K and the air filter every 30K, that's it! The same coolant and plugs stayed in there for 102K miles when it was returned. I did do a lot of highway driving, but also TONS of idling.

[ March 25, 2003, 12:44 PM: Message edited by: dagmando ]
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