Questions about switching oils due to high mileage

[rwinsouthla]

Hey guys,

Newbie here, just a couple of other posts. I am thinking now may be a good time (or was some time ago) to change to the high mileage oil. But I have some questions. Can I get your opinions on them? I currently use Castrol 5W20 and Motorcraft filters and always have. The Expy is a 2006, obviously 5.4L 2WD with 148K miles. Truck runs great...only thing ever changed is the coil packs about a month ago.

1. Should I start using high mileage oil? Why or why not?
2. Should I use conventional or synthetic or a blend and why?
3. Does high mileage oil have additional surfactants in it that could knock something loose or is that just internet BS?
4. What brand of oil should I use or do you guys prefer?
5. Should I increase or reduce the weight of oil I use since it has high mileage? Keep in mind that our winters are like your springs and falls, and summer is 92-96 deg F with brutal humidity and lows of 80 or so at night and last from end of April to October. Point being...it's friggin' hot here!
6. What does high mileage oil have in it that conventional oil doesn't?

Thanks in advance for your opinions.

Ray in South Louisiana

 

[01yellerCobra]

I never ran high mileage oil in my old 302. And it had 190K on it. I figure if it ain't broke why fix it?

 

[Whack]

Oil change interval is really the most important issue. If you are regular about changing at 3000 to 4000 miles on the Castrol, you are fine.

Should you start high mileage oil? Yes and no... the high mileage formulations normally have extra stuff to keep seals soft and able to maintain a seal. There isn't a lot of special 'wear reducers' then regular oil. It really depends on the engine... if they are prone to leaks with age, a high mileage could buy you some time. I'm not too worried yet on mine. SO I just run a good synthetic.

Regular or synthetic? Depends on oil change intervals and engine condition/design. If you don't push past 3000 mi on regular or 5000 on synthetic, you will be fine. The only way to really tell is with oil analysis. Some engines are more prone to sludge then others. The 3V V8 isn't too bad on sludge, but with the set up of the VCT, any sludge is bad. I don't fault the engine to much, I just know you have to keep it clean. Best bet, oil changes often and use quality oil and filters.

High Mileage oils normally don't have 'extra' cleaners... Normally they are just quality oils with good additive packages (including surfactants, anti-oxidents, anti-wear additives).

Brand of Oil? I like Mobil, but anything that meets API specs is ok.

Oil weight change for High Temps? Not really. The Mod V8 has pretty tight oil clearances and a VCT systems for the Cams that requires some consistent oil pressure. Normally, swapping the oil is dependent on oil temp in the engine. Ideally if the oil is at high temps and high work loads, there is a chance that a 30 weight (think 5w-30) would be better suited then a 20 weight. This only happens when a the oil is pushed hard enough that the 20 is too thin and a 30 weight could bring in the correct oil film thickness under those conditions. At higher RPM and ambient temps, I feel a 5w-30 could be needed in our engine... Big question is do you haul a trailer or heavy loads in higher then normal RPM ranges? I will haul gear in 90 to 95 degree temps in STL on either 0w-20 or 5w-20 all day long. If I get the trailer I want, I would add an oil cooler before swapping up to 5w-30.

Lastly, high mileage oils normally only contain seal softeners to help seals maintain their seal. Some may claim to add more wear reducers, but I get the feeling that a good synthetic will make up for that.

Full disclosure: I use mobil 1 0w20 or 5w20 on my Expy with a Motorcraft filter. I do a 5000mile oil change interval. It comes out pretty clean.

 

[1997SCEBFEX]

nice reply Whack.

PanHandler.

 

[rwinsouthla]

^^+1 for the reply Whack. Thanks very much. On you question about hauling stuff...nah. Pretty much daily driver 80 mile round trip at 55-60 mph, very few stops, and I start/stop very gingerly. Once a quarter or so I might haul a lawnmower on a trailer or something, but the thing has never been stressed.

Thanks again for the time you took to capture your thoughts. Much appreciated!

 

[tonydiv]

I was really happy with the fully synthetic Valvoline Max Life high mileage oil. My truck never lost a drop of oil on the driveway

 

[ELVATO]

If you've always been using that, then there should be no need to switch.

I use Castrol Syntec stuff with the 820S filter with 5000 mile intervals.

 

[Whack]

rwinsouthla,

More then likely you are fine if you keep to the oil changes.

If you ever wonder or worry about it you could grab some used oil at change time and ship it off for analysis... I've used Blackstone once on my daily driver Subaru:

Blackstone Labs

Test runs about $25 bucks. Can tell you a lot about how the oil is being used and a little about how you engine is doing by what it puts into the oil.