RedLine MTL - BIG improvement!!!!

One DOWN side re MTL in my 328

Although the shifting in all forward gears on my 328 is dramatically improved as I stated earlier, I have found that shifting into reverse is noticeably more difficult now. Previously, with the Motul, shifting into reverse wasn't a noticeable problem - I just shifted into reverse. With the MTL it will grind every time unless I shift into 1st gear and THEN into reverse. In that case, it goes easily into reverse. I have read that that grinding into reverse is fairly common and the "fix" is to shift into 1st first. but I had not experienced it with the Motul. That being said, even if I had to shift into reverse before starting the engine, I would happily do so for the improvement MTL made in the overall shifting.

 

I was impressed with the video because NOT ONCE did he recommend using Red line products. It is seldom you see such an objective presentation by a representative of a company that sells things!

Excellent info for anyone with some of the typical lube questions.

 

Re oil temp - on the gauge in my 328, the oil temp in normal driving stays around the 210 mark or slightly under that. ASSUMING the gauge is at least in the ballpark, that would indicate that the oil running at its spec weight. As he pointed out in the video, track use would probably likely that temp considerably, and a grade heavier would be better for that purpose.

However, that method (temp) is not what we used to decide on oil weight...

We always selected oil viscosity based on oil pressure at operating temp. I have to say that to me, looking at temp to decide viscosity is sort of "back-dooring" the question. If the oil pressure is sufficient throughout the rev range in the conditions appropriate (track, street, whatever), than the lowest weight that produces that pressure is correct; anything heavier is just wasting HP. Obviously, temp is important in the sense that if it goes high enough, any oil can break down but that level of heat is extremely unlikely, especially with synthetic oils. Also, cars are more likely to have an oil pressure gauge than an oil temperature gauge so it seems to me that checking pressure is easier as well. Since what you are worried about at all times is that there is sufficient oil pressure in the system to do the job, looking at the oil pressure in the situation is the direct "answer" to the question of whether the viscosity is sufficient for the application. To me temperature is an indirect way and might even produce an unnecessary change. If the pressure is OK with, say 40 wt at 240F, there's no reason to put 50 wt in.

I think I will send a message asking his views on the point, above. I would be interested to hear his view on why pressure was not considered. There could be something here that I need to learn!

 

It's not really necessary to know anything about the volume. The manufacturer of the engine determines what the pressure should be to provide proper lubrication based on the system and the engine clearances. The "volume" of oil per second (or minute, whatever) it takes to do that is automatically "correct" if the pressure is within spec. Therefore, pressure is all you really need to know; if the pressure is satisfactory, the volume of oil is also satisfactory by definition. If the standard oil pump in good condition cannot supply sufficient pressure, the engine needs to be rebuilt because the clearances are excessive.

OTOH, competition engine often use a high volume oil pump because they frequently have large internal clearances compared to production cars. In those cases a high volume pump can supply sufficient pressure when an OEM pump may not be able to do so.

FWIW, the standard 10 PSI per 1000 RPM under load has been a standard for a LOOONG time and it is still pretty much the common application. The Red Line guy, however, made an excellent point that I had never thought about - the fact that many modern engines that use variable cam timing (He specifically mentioned BMW) need oil of a certain weight to operate that system properly. So, in that case, viscosity may be dictated by that system, not the "rest" of the engine. Interesting stuff.

 

Yes, the volume of oil IS the goal but the pressure determines the flow (volume) based on the clearances in the engine and oil passages in the system. The engine manufacturer has (hopefully) determined the pressure needed to provide that volume and given a pressure spec for that - like Ferrari's 85 PSI at 6500 RPM. So you don't need to know what volume the Ferrari engine needs - Ferrari already figured that out and publishes a pressure spec to achieve it.

Yes the volume delivered DOES change with temperature and viscosity BUT, again, as per above, the manufacturer of the engine determines and publishes the spec that automatically ensures the volume is adequate if the pressure is adequate. IOW, any difference that actually occurs with flow (volume) based on temp/viscosity doesn't matter - it still falls within the range that provides adequate engine protection.

That's not to say there can't be a problem if, as noted earlier, oil that is too heavy is used. In that case,I suppose it IS possible that insufficient oil could be moved through the necessary areas even though pressure is OK. Seems to me that would require oil that was much heavier than what the manufacturer recommended but I guess it could happen, especially with a cold engine using straight-weight oil.

I got a nice response a few minutes ago from Red Line; I did not ask Dave if it was OK to post his response here so, to paraphrase, he suggests that temp and pressure are both important and that if oil pressure is too low, a higher viscosity oil can help. He points out that if higher viscosity oil is used it will also operate warmer and that many times the higher viscosity oil is a band aid for other issues. He restated his point in the video that if say, 40 wt is spec and you go with 30 because pressure was still OK, it "might not provide the protection expected.":

 

It's ironic, I have never in my life used a Redline Product until I bought MTL (per RifleDriver) a week ago! But I'll see what I can do with my new friend Dave at Redline. I'll also ask if he's ok with me posting his response(s) as direct quotes.

 

Response from David is that even with modern synthetics, Including Redline products, the oil should be changed annually because the oil's additive package deteriorates over time and gets further used up holding contaminants in suspension. This is not related to engine operation (mileage) just time.

 

Just a FWIW note that probably everyone already knows as far as using GL4 (like Redline MTL): the data plate in the engine compartment (at least on my '89 328) specifically states to use GL5; the owners manual lists AGIP Rotra SX as appropriate which is also a GL 5. I'm sure the 5 is specified to ensure the differential does not chatter in a tight turn but I've not yet heard any chattering from my 328 since I changed to MTL.