Case of no maintenance

Too bad the factory fill wasnt Redline Oil (didn't have back then) as he would have done a lot better (though beyond their recommendation too). You'd think at least he would have changed out the break in oil.

TallPaul:
SynLube must have been invented for just such circumstances.

Several of these companies should pay to do a study where their oil is purposfully abused. New taxis. At 3000 miles they are changed to 3 taxis each of Royal Purple, Redline, Synlube, whatever others want to participate. Then no more oil changes. There should be no filters to clog, just a cover to allow the oil to pass the filter location. Then run the taxis 50,000 miles and tear them down and measure wear. Good test?

TallPaul,
I'm not sure a Taxi cab test is of interest apart from oil performance is similar i these circumstance along the lines of the Truck example

http://www.xs11.com/stories/croil96.htm

Oils need to be stressed to to see if the performance is enhanced.

Start up
Short jouneys oil not reaching operating temp
High revs
High speed

Thicker is not always better, it’s the “shear stability” of the oil that’s even more important than the viscosity when the engine is stressed over long periods

For example 300+bhp Peugeot-ice-racer-bodied hybrid with the normally asthmatic
Cosworth in the back.

The engine needed to be stripped after every event normally 45 miles,and change the big end bearings every time.

Using an ester based oil the engine was stripped after it's 4th event
(approx 200 competitive miles!), and there isn't a mark on it.

I am aware of the CU taxi test and its problems. I picked taxis because they would get the most consistent use across many vehicles, or so it seems. Rentals might be better, but could have more variation in usage? Anyway, my test is extreme in one sort of way. Racing use appears the better test, as you say.

Tallpaul,

I see you posted some interesting articles.

Amsoil like to show off tests and how good their oil works.

From a motorsport point of view esters are used and have been for a long time with Castrol Castor oil which is base for Silkolene products which for road are PAO and about 20% ester.

RL and M1 come from similar direction and give a good mix.

For general road use its more value for money and does a little extra ester make sense.

MGBV8: I think some ester for regular road use would be good. Just don't know how much. Interesting is that (according to BITOG posts) Valvoline Maxlife had esters mixed in, but later (maybe 2002 or 2003) it was switched to PAO (current MSDS says 12-22%). So I wonder why they went with esters in the first place and why they switched to PAO. Well cost would be a good reason why they switched from ester to PAO.

I also visited the Australian Redline site (www.redlineoil.com.au) and found some interesting stuff such as this: "100% man made synthetic which contains no impurities and can assist in the removing of impurities from an already contaminated system."

TallPaul
There may be a problem with Maxlife hence change!
http://www.car-forums.com/s9/t3517.html

Synths are normally avoided with high mileage because of cleaning can clog the engine but also remove the gunk around seals that stopped leaks.

Auto rx may do this safely compared to a synth, but I've never risked a change to synth unless a rebuilt engine.

MGBV8:

Consider this post re high mileage oil from the oil guy site:

"There have been many people that start using a high mileage oil with good intentions. Then seapage and leaks start and it's time to quit using the HM oil, because it has caused seaps and leaks!! I experienced the same situation. The key is to keep using it. The seapages are caused because the previous oils allowed buildup and sludge to cover the gaskets and oil wouldn't even get into that area to leak. The HM oils clean out the 'crud' and expose the gasket materials, which usually at that point are getting brittle and dried, therefor allowing the oil to seap or leak. This can be when the driver becomes alarmed and stops using the HM oil. Well, the bottles should explain the process better. It is annoying to see the leaks, but that is when the HM oils are able to swell and repair the gaskets and seals! I have been using Castrol HM in my father's Taurus. After 3 oil changes, seapage was occuring. He bacame alarmed at the leak. Then the store only had Castrol Syntec Blend, which made the seaping worse!! After the switch back to the HM oil, the leaks have stopped. He is happy, and we now understand why the leaks started and stopped. I hope this helps!"

This problem may be more common with the ester fortified HM oils as the ester may clean better.

I've been running synthetic blend in all my vehicles from probably about 60,000 miles on out. Likely was Group III in the mix.

I don't think AutoRx conditions seals, but the dino (conventional) oil does, at least it seems from what I have read at the AutoRx site.

Plan on switching wifes van at 104,000 from synthetic blend to full synthetic Valvoline Synpower (got 6 qts free). I don't anticipate a problem as it is similar to the Durablend it had run for a long time, but now will be all Group III (or highere?). If it leaks, back to Maxlife or AutoRx.

TallPaul,

Good info, is auto-rx really necessary as expensive and may only do same job as a good oil?

I wonder that myself. In my ARX treatment cycle I only noticed the filter looked like a 4000-mile filter after only 1500 miles of treatment, but my database of what used filters look like is very limited.

Now 500 miles into the cleaning cycle the oil is very clean looking on the dip stick. Well, too soon to tell.

I do think the AutoRx is more agressive at cleaning than Redline. But 12 oz ARX mixed with regular oil may not be as agressive as a whole crankcase full of Redline, but then it is about as expensive or worse.

I was not sure the high mileage oils could do that much cleaning so quickly, and maybe it does. If so, then the heavy duty oils like Delvac should clean also.

quote:

---

Originally posted by MGBV8:
TallPaul
There may be a problem with Maxlife hence change!
http://www.car-forums.com/s9/t3517.html

---

That member in the linked forum was ignorant to the fact that motor oil will not affect a head gasket .

I think you will find high mileage oils use combo esterfied additives synergysticly to clean and keep engine seal pliable .

Paul , did you say you have a rear main seal leak now after using a cleaner in your engine ?

On another note ,
Not everyone can get the Mobil HM product that does clean but a few intervals on that oil would be the logical choice before resorting to a dedicated cleaner .

I believe the rear main seal leak has been there for a long time. I only noticed the seepage was farther down the pan during the Auto Rx treatment. Nothing dripping on ground. I wiped it off and it seems very controlled so not sure it is even aggravated by the cleaner. See the Auto-rx.com site for more info.

Right, I was thinking that myself, that a head gasket is composed entirely differently and the oil would not get to it anyway.

quote:

---

Originally posted by TallPaul:
MGBV8:

Plan on switching wifes van at 104,000 from synthetic blend to full synthetic Valvoline Synpower (got 6 qts free). I don't anticipate a problem as it is similar to the Durablend it had run for a long time, but now will be all Group III (or highere?). If it leaks, back to Maxlife or AutoRx.

---

I have switched a Toyota Tercel with approx 60,000 miles over to full synthetic (Mobil 1) without a problem. Previous to that I switched a vehicle with approx 80,000 miles with no problem. Also, a person here in the office who has a Ford Crown Victoria with approx 100,000 miles switched over to Castrol's Syntec with no problems.