The mechanic who does work on my husband’s Dodge truck gave us some advice concerning oil brands. He says that brands such as Quaker State and Pennzoil contain paraffin which, over time, will build up in the engine and cause sludge. He recommends Havoline, Valvoline or Castrol. Has anyone heard this before? Do you know about other brands such as Mobil, which our Mazda service shop uses?
Is this mechanic an old-timer? I suspect he’s been around the block more than once. His advice is left over from the '50s and '60s, and probably originated a generation earlier when Pennsylvania still had active oil fields.
Motor oils refined from Pennsylvania crude was rich in high-molecular weight hydrocarbons, known to chemists as paraffins, and thus was prized for use in high performance racing engines.
None of this is true today, if indeed it ever was. You’ll probably not find any significant differences in any of today’s brands. Still, old myths die hard.
I agree, I wouldn’t worry about paraffin in modern oils, just buy the best quality oil you can find to meet your engines specs. (Mobil 1, etc) and don’t worry about the specific contents of the oil.
This was funny for me to read as my Father has told me the same thing. He’s 65 years old now, so he comes from the days of genuine Pennsylvania oil. Just as a side note, if you want to get Valvoline on the cheap, CarQuest brand conventional motor oils are Valvoline in disguise at half the price.
Put ANY motor oil that meets the proper spec and grade according to your owners manual and change at manual prescribed intervals and your motor will long outlast the lifetime you own it or even the overall vehicle itself.
I wouldn’t agree with using ANY oil. The cost difference between the cheapest and most expense is negligible compared to the cost of an engine. I can still change my oil with the best oil available for under about $70, so IMHO it’s pretty silly to use cheap oil to save a couple of dollars unless you consider your engine/car disposable. Sometimes you do get what you pay for.
$70 for an oil change? Yikes! Unless of course you are talking about a synthetic and actually go 15000 miles between changes.
I’m interested in learning what Craig thinks is the ‘best’ motor oil. I’ve been using Castrol GTX for years in my Toyotas. My 1990 Pick-up truck was still running strong with solid oil pressure and no oil burning at 325,000 miles on a steady diet of the stuff. I was shooting for 1/2 a-million miles until a retaining wall had other ideas. My 1988 Supra is also running strong with 233000 on the clock. I generally change the oil at 4,000 to 5,000 miles. The oil barely looked used at 3,000 miles.
My experience has always been a quality oil and regular oil changes are best. I’ve had discussions before with friends about Castrol, Valvoline, and Pennzoil. But, we all seem to have the same result in the end. Just use a quality oil that meets the manufacturer’s recommendation, and stick to the severe use maintenance schedule. You can’t go wrong that way.
I have a couple of diesel cars that hold about 8 quarts of oil. Good diesel rated synthetic costs about $5 to $7 per quart. Probably the “best” mainstream synthetic diesel oil is Mobil 1 5W40 “turbodiesel” (which is similar to the “ESP” Mobil 1 5W40 that the benz dealers use). OEM filters cost about $15 each and I change it every 5000 miles (due to soot loading). My daily driver has almost 400K miles at the moment, and is running very strong. My other diesel car only has about 215K miles (just a pup). Castrol is perfectly good oil (I used to like it for air cooled vw/porsche engines), but is not diesel rated AFAIK.
The economics are pretty simple, I will eventually have to have my engine rebuilt (probably about $8000, including installation) so I’m not that interested in saving $20 by using crappy oil. I drive this car about 40K miles per year, that’s about $500 per year for oil changes. I hope to avoid rebuilding the engine until at least 500K miles. I will gladly pay $500 per year to defer an $8000 expense. I would rather rebuild my engine for $8000 than pay $60,000 for a new car.
If you have a car that you are going to run into the ground in 100K miles, or sell within a few years, it probably doesn’t matter what type of oil you use.
He’s not what I would call an old-timer; he’s probably in his 40’s or so. He says that he has repaired several engines that were gunked up from use of oils containing paraffins.
$8000 on a $4000 car with 500k miles is interesting economics. However if you love it go for it 
No one is going to buy mine for anything close to $4000, not even with the original engine. The economics are very interesting, a friend of mine just sold his 84 diesel (decent condition, far from perfect) for $12K, mine’s not for sale.
Regarding oil, my point was that it does not make any sense to treat an expensive piece of hardware like a disposable appliance just because you can unload it on someone else who doesn’t know any better in a few years; then buy something newer to abuse for the next few years. Not only are you hosing the next owner, you are continuously spending money on the next disposable appliance.
no its true, im a mechanic, everytime i overhaul an engine i can tell which ones have used penzoil, i suggest rotella t
Quaker State and Pennsoil USE to come from Pennsylvania oil fields. They’ve been closed down for almost 30 years now. And it WAS true that they contained higher concentrates of parrafin. Not sure if it caused sludge though.
I myself prefer Mobil but unfortunately they no longer make the conventional oil its all now syn-blend or all out synthetic(I run the synthetic in my wifes 97 Grand Am GT) change a filter every 2k for 8-10k miles and then do a complete change. I still have one case of conventional that I use in my 83 T-10 then I am switching to Valvaline or havoline(which ever I can get the cheapest on sale and is the same oil). I run Shell Rotella-T 15-40 in my 1979 Monte Carlo that has a fairly stout 355. For many people they don’t know that many brands of oil are made by the sam manufacture. IE
penzoil, shell and I believe quaker state are the same.
Diesels. That explains it better. Of course, diesel engine oil is spec-ed differently than gas engine oil. And, they tend to hold twice as much oil as typical gas engines. Kudos on the longevity.
Some diesel trucks really hold a lot of oil, the biggest difference in the oil is it’s soot retention capability.
I still maintain that using high quality oil is important in any engine that you intend to preserve. It sounds like castrol is working well you, 325K miles ain’t bad.
There is a special place for oil obsessives;
The most important factor about motor oil is CHANGING IT!!
Most cars no matter if $90k MB or $12k Hyundai in our our locale(New England) turn to junk around 14-20 years due to rust from road salting. Vehicles in New England are disposable consumer goods. Obviously exceptions but rust seems to get most of the cars.
Agreed
My parents and my experience on cars is that simply changing it even with dealer/garage bulk fill on regular basis (~5000 miles) gets you about 12-15 years with a perfectly running car with never an oil related engine problem but rust has eaten it to bits(New England).