High mileage oil?

[Road Angels]

Wow you guys buy new oil? I change my wifes oil every 3k then dump it in my 86 ranger 2.3 and run it another 3k wish the filter inner changed, so that gets changed about evey 8k or when I remember, but I do grease her joints regular, 300k and counting on 12psi oil pressurer

 

[oldcrowalki]

Wasn't aware you could mix the 2. Heard once you use synthetic you can't go back.

If this were true, why would they make a semi-synthetic?

 

[bmerr98]

If this were true, why would they make a semi-synthetic?

So your engine doesn't get the DTs from quitting cold turkey

 

[lil_Blue_Ford]

I was always told that HM oil had additives to swell gaskets and not to break up too much crud that could be holding things together.

I was also always told that the problem is not switching from synthetic to regular oil, but from regular to synthetic in a higher mileage motor because synthetics tend to be a little runnier than regular oils and sometimes have better cleaning properties, thus it can free up crud and make any leaks you have now worse.

I ran regular oil for years. I switched my Ranger over to full synthetic after reading through some reports on it prolonging engine life and the fact that it tends to hold up really well. My F-150 supposedly had 69k miles on it when I got it. I think the first oil change or two I did in regular oil and put a shot of ATF in with it to swell the seals. Then I went to semi-synthetic for a change or two with a shot of ATF. Then I went to full synthetic (Mobil 1) and extended my oil change intervals to 10k.

My F-150 did leak oil bad. It was almost to the point that it was pouring out the side of the block through the pushrod cover. So when I rebuilt my front clip recently, I pulled the cover off to find the original cork gasket has converted to a charred crisp and wasn't sealing anything. Since putting a new rubber gasket in (Felpro) with some Ultra Black RTV to make sure it sealed good, no more leaks. Sometimes you just have to get in there and fix a leak, after seeing how bad that gasket was, there was NO oil (at least short of maybe a bit of straight crude) that was going to plug up that leak.

I had an 89 Bronco II Eddie Bauer back in college that I used as a campus beater mostly. It didn't really leak out of the valve covers and it didn't seem to be burning oil, but I was always down some. After awhile I noticed that it was spraying a mist of oil out of the exhaust. I scratched my head, asked around a bit, and finally broke down an bought a new PCV valve (I had cleaned the one that was in there twice). After putting the new PCV valve in, no more oil loss. Apparently the spring was too weak in the valve to properly control the oil flow.

 

[simpler=better]

Wasn't aware you could mix the 2. Heard once you use synthetic you can't go back.

You can go any which way

My truck, the Wifey's Jeep, they both get synthetic everything (diffs, transfer cases, transmission, oil). 0 issues, no new leaks, and improved performance.

 

[bigmark303]

The High Mileage oil for sure has gasket swelling additives. Ive had a somewhat leaky rear main seal (few drops each day) in my 1997 4.0L with 192k on it. Ive always used the high mileage non synthetic oil and recently at 189k started using the Motorcraft synthetic 5w-20 because I have a ton of it.

Sure enough that synthetic oil cleaned out the buildup around the gasket and is seeping by the gasket more and more as the high mileage swelling additives wear off. Ive changed the oil every 1,000 miles since 189k because of hard use and next change (193k) before it snows im going back to the high mileage oil to cure that gasket leak.

 

[exbass94]

ALL oils are fully mixable. You can switch back and forth between conventional and synthetic as many times as you want, you can mix them together, you can switch back and forth between high mileage and regular as many times as you want and you can mix them together, etc etc. The oil will not turn into some horrible goo when mixed with something else. It usually says right on the bottle that it's compatible with other types of oil.

I used to use synthetic in the Explorer for a while, decided it wasn't worth it and switched back to conventional. It hasn't exploded into a million pieces yet.

 

[Chris_North]

I was getting the infamous oil pressure gauge flicker, so I installed an analogue OP gauge. With basic store brand oil I was getting 20 PSI on the highway and coming to stop in gear it would often drop to 5 PSI. I changed the oil (which only had about a thousand miles total) to high mileage valvoline oil and I get a lot higher cold engine pressure (60 PSI versus 45), 30 PSI highway, and even when coming to a stop after hard driving I still have about 12 PSI. Hardly scientific since I also went to a different brand filter, I am probably only just passing the amount of miles on this oil as the last when changed, and the ambient temps have dropped about 15 degrees Fahrenheit.

 

[simpler=better]

ALL oils are fully mixable. You can switch back and forth between conventional and synthetic as many times as you want, you can mix them together, you can switch back and forth between high mileage and regular as many times as you want and you can mix them together, etc etc. The oil will not turn into some horrible goo when mixed with something else. It usually says right on the bottle that it's compatible with other types of oil.

I used to use synthetic in the Explorer for a while, decided it wasn't worth it and switched back to conventional. It hasn't exploded into a million pieces yet.

YET...they call them Exploders for a reason

 

[ZMan]

Ya, because of the tires blowing causing them to rollover lol ( mostly driver error)

 

[Dugan]

I use to run highmileage and a shot of lucas in mine 330k 2.9.. then i went to I think 10/30? Mobil.. The motor loves it

 

[Kody165]

I dont drive enough to put on 2,ooo miles in a year. i change mine with castrol synthetic blend every spring. 87 2.9 with 450,000 miles. leaks a little bit at the valve cover but not enough that i have to add oil. AS long as you treat your engine with respect, arent an ass to it, and keep it happy it will serve you for eternity!