I know its been covered time after time but here it is. I have a 97f150 with a 4.6 sitting at 190k miles. I use motorcraft syn blend 5w20 with motorcraft filter every 3000-3500 miles and it still,runs good. I see some guys online that say that 5w30 is better. A couple of guys i work with tells me that oil is oil and it dont matter(i dont believe that a bit) even though i know you guys have seen it a million times but interested to hear input and advice.thanks

 

Either is fine. If you are using 5w20 and it's not burning it, just keep using it. The original spec in 97 was for 5w30, but Ford updated the spec in the early 2000's to 5w20 for a little better gas mileage. The Motorcraft synthetic blend is as good as any.

 

x2 on glc.

I use Motorcraft 5w20 in all my gas powered vehicles, including my gas riding lawn mower.

Most of the time it is ironically cheaper than most name brands.

 

Does anyone know the ratio on the MC synblend oil? Is it 50/50 more or less?

 

No idea, but the test numbers are competitive with so-called full synthetics.

 

Hey glc, whats your oil brand of choice? Just wondering because im hearing good things about pennzoil and was thinking of trying it.

 

I have a 4.2 V6 which is an old school pushrod engine, not an OHC like you have. I use Mobil 1 EP 5w20 and a Mobil 1 filter, and change it once a year. 192k on it and it burns a quart about every 5k. I'm not saying that it's the best, but it's what I use.

 

I have switched to 5w30 in my 02 5.4 (151Kmiles) using a syn blend. Not saying that's the best decision. Who knows? But that's what I did. I change it at 5k miles. It uses a qt in 5k miles and being a little ****, I add a pint at 2.5K miles.

 

Ok, you guys are probably tired of my lack of basic oil knowledge. With that being said, heres my issue. The previous owner of my truck ran synthetic and ive been running MC syn blend since ive owned it(a little over a year) i now have an opportunity to get my hands on pennzoil full synthetic for really cheap but im concerned after reading and hearing rumors of engines getting leaks when converting from conventional to synthetic oil. What do you guys think of that? My 4.6 doesnt really burn or leak oil between oil changes so should i be concerned? The deal is hard to pass up price wise.

 

That's no longer a concern with today's engines and any of today's oils. Go ahead and switch. Just make sure it's an appropriate weight and you use a quality filter.

 

I keep seeing cases of 12 bottles of 5w30 dino and/or syn blend oil in Sam's Club for $21.48. It's made for Sam's Club and is supposed to meet the API spec SN. It's sorta tempting.

 

Sam"s Club "Certified" motor oil in 5w-30 is made by Reliance Technologies out of Niagara Falls. They blend for a lot of off brand motor oil sellers. It should say Dexos 1 compliant on the bottle and is a GF-5 SN oil. Two things about it, one good, one bad. The bad.....the ASTM D5800 testing for high heat is a dismal 14.9%. The absolute max for any API oil is 15%. So it's not going to do well in a worn engine or in a high heat environment. The good....it has roughly 217 ppms boron in the formulation. Boron is an expensive additive that helps carry the load when things get hot. If you change at 3000 miles by habit, this is just an okay oil to use. I wouldn't suggest running it farther or expect sludge and varnish inside the engine. The detergent package is reasonable but weak hence the cheap price.

Any Pennzoil motor oil will be better than the Sams Club. The synthetic is the best synthetic out there as of now. But frankly, why spend the bucks when the yellow bottle blend is so good. The 10w-30 is still good at temps down to -25C for cold start up. The ASTM D5800 testing yields an astounding 4.6% and that my friend beats any synthetic available at any price. I'm running it in my 3.7 F150. No drop in gas mileage and no issues with cold start ups. As far as I'm concerned, it's the best motor oil you can put in any street engine.

In regards to using a synthetic or a blend. Back in the 70's and 80's when synthetics were becoming popular, the formulators did not include anything for the seals. Dino oils have natural occurring saturated fats that keep the seals supple. The synthetic base oils of the day had a great amount of solvency and therefore would clean any crud around the seals. But because the synthetic oil did nothing for the seals, leaks happened. Since then the formulators include a seal swelling agent to take care of the issue. You can literally swap back and forth all you want. FWIW, Mobil and Castrol had an issue with Castrol claiming the Gp III base oils were a synthetic. The Advertising Council found that because it does not appear in nature, that it is a synthetic base oil. Mobil has since dropped the GP IV base oils and their synthetics are now Gp III. BUT, since oil prices have gone up, there are motor oil makers out there that have stretched the definition to include everything as a synthetic base except for the solvent refined GpI base oil. Buying and paying extra for yesterdays dinos as synthetics is unfortunately more common than you want to know. Buy a name brand oil, don't pay a lot for it, and change according to the auto makers extreme service guide and you can't go wrong.

ASTM D5800 testing is a test where the oil is exposed to 302F temps for one hour. The oil is weighed before and after the test. The difference or numbers you see is how much, expressed in percentages, that the oil lost due to the oil cooking off. ILSAC says 15% is max. Most synthetic oils will be around 10%. The yellow bottle 10w-30 at 4.6 is a reflection of the quality of the base oil used to make it.

 

Labnerd, I was hoping you would chime in! Thanks!

 

x2 on glc's advise.

In my other vehicle (07 Jeep Compass 2.4l World with over 280k), I think every brand of 5w20/30 has been in it, dino, semi-syn, full syn, etc. Along with all kinds of filters. No problems to report. Still ticking like a time clock.

The old wives tale of switching oil is nothing but hogwash now a days.

 

Your right you shouldn't believe the guys at work when they say oil is all the same,it not. Some oils are too thin and don't offer enough protection from friction. others are too thick and can cause other excessive pressure or not provide the lubrication the motor requires. Car Manufacturers spend a lot of money in research to determine the proper oil required for each engine, but this is when the engine new or like new .
Trying to Determin the right oil in motors with high mileage is kind of a crap-shoot because you can't tell how much wear is inside the motor. If I were going to choose a high mileage oil to put in my car I would see what the manufacturer recommended.