I wanna use a non VW approved "thin" oil in my GTI

[RooflessVW]

We're not talking about your naturally aspirated Mercedes. This thread is about the merits of thin oil in a modern GTI.

The applications are totally different here.

Deven,

Isn't RP's 5W-30 HTHS like a 3.8? If so then it's more like a 40, and should have sufficient film strength. Yours is a case of finding a non-approved oil that meets the set requirements,and may be more optimized for your intended useage. If your car was unmodified and street-driven only, would you run the same oil and change interval?

For street use, and when taking cost into effect, I'm not sure you can beat an off-the-shelf 502/505/M229.5/A40 spec oil.

 

[VeeDubb]

I agree with rooflessvw. These engines are notorious for cam follower wear. There are so many threads about this on vwvortex and Audi forums, that the OP should read some of these before throwing caution to the wind.

 

[deven]

Originally Posted By: rooflessVW
Deven,

Isn't RP's 5W-30 HTHS like a 3.8? If so then it's more like a 40, and should have sufficient film strength. Yours is a case of finding a non-approved oil that meets the set requirements,and may be more optimized for your intended useage. If your car was unmodified and street-driven only, would you run the same oil and change interval?

For street use, and when taking cost into effect, I'm not sure you can beat an off-the-shelf 502/505/M229.5/A40 spec oil.

RP doesn't disclose HTHS for their HPS oil but with my emails to RP about it, they have hinted to it being closer to 3.5.
I use RP HPS in every engine regardless it's intended use. I can get the HPS for $7.50 per quart so it's not that bad a deal but yes VW approved oils would be a little cheaper for sure.

 

[kschachn]

Originally Posted By: deven
RP doesn't disclose HTHS for their HPS oil but with my emails to RP about it, they have hinted to it being closer to 3.5.
I use RP HPS in every engine regardless it's intended use. I can get the HPS for $7.50 per quart so it's not that bad a deal but yes VW approved oils would be a little cheaper for sure.


So you are using an oil with no manufacturer approvals in an expensive car and engine, based on "hints" you glean from an email conversation?

Plus you are paying more for it to boot?

 

[deven]

Originally Posted By: kschachn
Originally Posted By: deven
RP doesn't disclose HTHS for their HPS oil but with my emails to RP about it, they have hinted to it being closer to 3.5.
I use RP HPS in every engine regardless it's intended use. I can get the HPS for $7.50 per quart so it's not that bad a deal but yes VW approved oils would be a little cheaper for sure.


So you are using an oil with no manufacturer approvals in an expensive car and engine, based on "hints" you glean from an email conversation?

Plus you are paying more for it to boot?

Yes. The engine warranty is long gone when I decided to tune it from 303 hp to 500 hp. Plus we just swapped out the factory cam for performance ones and the RP is doing very well. Everything is like factory new and the factory cams measured factory spec.

 

[RooflessVW]

Originally Posted By: VeeDubb
I agree with rooflessvw. These engines are notorious for cam follower wear. There are so many threads about this on vwvortex and Audi forums, that the OP should read some of these before throwing caution to the wind.


We're talking about the TSI in this thread, but for some more carnage, plug "pumpe duse damage" into Google for another example of why "thick" oils can be critical when specified by the manufacturer.

Unless you plan on measuring some critical items periodically as Deven has done, best to stick to the manufacturer-specified oil.

Deven, furthering discussion, if you had discovered cam follower wear when you changed the camshaft, what oil would you have chosen? A RP 5W-40, an approved oil, or something else? Are you concerned with big-end rod wear over the long term?

 

[HTSS_TR]

Originally Posted By: rooflessVW
We're not talking about your naturally aspirated Mercedes. This thread is about the merits of thin oil in a modern GTI.

The applications are totally different here.

Deven,

Isn't RP's 5W-30 HTHS like a 3.8? If so then it's more like a 40, and should have sufficient film strength. Yours is a case of finding a non-approved oil that meets the set requirements,and may be more optimized for your intended useage. If your car was unmodified and street-driven only, would you run the same oil and change interval?

For street use, and when taking cost into effect, I'm not sure you can beat an off-the-shelf 502/505/M229.5/A40 spec oil.

Originally Posted By: VeeDubb
I agree with rooflessvw. These engines are notorious for cam follower wear. There are so many threads about this on vwvortex and Audi forums, that the OP should read some of these before throwing caution to the wind.

I shouldn't post without learning that the newer GTI has turbo charged engine, I though that it had the same naturally aspirated engine of the early 2000.

My apology.

 

[deven]

Originally Posted By: rooflessVW

Deven, furthering discussion, if you had discovered cam follower wear when you changed the camshaft, what oil would you have chosen? A RP 5W-40, an approved oil, or something else? Are you concerned with big-end rod wear over the long term?

Well I did use RP 5w40 for an OCI but changed to RP 5w30 HPS as it has more anti wear additives and higher film strength. But to answer your question if I had found cam follower wear oil with RP then from my experience no VW 502.00 oil would prevent it either. What I would have done would be to change to Red Line 5w40. High HTHS and very shear stable changed out 5-6000 miles.
We don't see much if any rod wear with the newer VW engines. We've seen VW engines with 100k plus miles with no big end rod wear so at the moment I'm not concerned about it.

 

[BrocLuno]

The difference here is that racers are actually in their engines often and they see and know first hand what is happening.

Road drivers may never see the underside of a valve cover in their lifetime. Big difference on using a lube and seeing first hand what works.

No MFG approvals needed. Racers know what they know and may not share with the general public.

I'm in this camp. When I tear and engine down I'm looking for specific issues. Cam and lifter wear being one of them. I have not built a full-on race engine in ten years. Just warmed over street engines now

 

[RooflessVW]

Originally Posted By: BrocLuno
The difference here is that racers are actually in their engines often and they see and know first hand what is happening.

Road drivers may never see the underside of a valve cover in their lifetime. Big difference on using a lube and seeing first hand what works.

No MFG approvals needed. Racers know what they know and may not share with the general public.

I'm in this camp. When I tear and engine down I'm looking for specific issues. Cam and lifter wear being one of them. I have not built a full-on race engine in ten years. Just warmed over street engines now

You're absolutely right, which I preach using manufacturer's approvals where required; it is the closest thing we have to a guarantee of performance for a given performance envelope.

 

[deven]

Originally Posted By: rooflessVW
Originally Posted By: BrocLuno
The difference here is that racers are actually in their engines often and they see and know first hand what is happening.

Road drivers may never see the underside of a valve cover in their lifetime. Big difference on using a lube and seeing first hand what works.

No MFG approvals needed. Racers know what they know and may not share with the general public.

I'm in this camp. When I tear and engine down I'm looking for specific issues. Cam and lifter wear being one of them. I have not built a full-on race engine in ten years. Just warmed over street engines now

You're absolutely right, which I preach using manufacturer's approvals where required; it is the closest thing we have to a guarantee of performance for a given performance envelope.

Yes I agree but at the same time we have torn down an engine where speconomic oil has been used and there has been issues like the cam follower issue we were talking about. Something VW admitted to and paid for the repair.
The good thing about racing and having the ability to tear down an engine is that you are able to punish the oil to its harshest environment and are then able to see first hand how it holds up. When you do this enough times with enough different oils you tend to see patterns develop with certain oils. This is the reason why I don't look at PDS, MSDS, or any mfg certs. When an oil holds up to the harshest environment time after time after time and in different engines I know exactly what to use in my vehicles.

 

[Garak]

Originally Posted By: HTSS_TR
My E430 can run up to 150-160 MPH at 5000-5500 RPM with M1 0W40 on autobahn for hours without problem. This engine is turning around 2500-2700 RPM at 75-80 MPH on So Cal hwy, no lugging what-so-ever. Once in a while I may accelerate a little hard, I may see 3500-5000 RPM for about 5-10 seconds, then back down to 2500-2700 RPM.

I wasn't suggesting that you were lugging, just pointing out that there is another point where a too thin oil could be problematic.

As for the rest of your post, be cautious so as not to discount HTHS, which won't necessarily track KV all that well. In fairness, my old Audi allowed ILSAC type oils under what we'd consider normal North American driving, or cold weather anywhere. Unfortunately, it just drank 5w-30 really bad, particularly M1. It was good with PYB 10w-30, but that's not idea for our winters. So, it got a 40 grade most of the time. Nonetheless, that vehicle was of the era that caused VW/Audi to come up with their own oil specifications in the first place. 12,500 km severe service intervals on conventional was a bit optimistic.

So, it was a German car, and it had a turbo. Yes, thin grades were permissible, and reasonable. But, driving habits matter as do OCIs. They didn't switch to oils with HTHS of greater than 3.5 for just one reason, or no reason at all. There were several factors, and one shouldn't go out of specification without careful consideration, that's all.

 

[Pontual]

Originally Posted By: Shannow
Originally Posted By: dareo
The hill was climbed anywhere in the 2s 3s 4s sometimes 5k+ rpm depending on the sharpness of the turns. I wasn't on throttle the whole time since i had to slow a bit for the turn, then power out of it. Temp outside was a cool 55f or so.

I think the oil temp is related to engine load so if i'm going 80 in 5th vs 80 in 3rd i doubt it will add much more heat to the oil. When i do my 40 mile highway runs it never gets above the 210-220 range even with A/C and as fast as traffic allows driving.


Nope, oil temperature is more related to RPM than load. Here's big end temp on a test engine (fitted out with thermocouples) with three bulk oil temperatures (80C, 125C, and 150C)...you can see that the temperature rise has more to do with RPM than load...the top group there is no continuation of the full load line, as the bearing failed.

Doing 65MPH in my Caprice, if I stop and drop a thermocouple down the dipstick hole, I get 105C...same trip in "2" at 4,000RPM, and 129-135C has been seen in quite mild ambient temperatures.

Not this is the oil that's coming off the crank and down the valley, not the bulk oil temperature that has already lost a lot of heat to the the ambient (sump temperatures with a heat gun are around 15-20C lower)


Heat is a co-product of work, right. If Load is doubled, same rpms, the heat is likely to increase a lot more than a few hundred of rpms on initial load, simple as that. No graphics needed to.Now if the oil system has flow/press restriction problems, the oil temp would raise a lot from rpm alone. Check restriction.

 

[KrisZ]

Originally Posted By: Pontual
Heat is a co-product of work, right. If Load is doubled, same rpms, the heat is likely to increase a lot more than a few hundred of rpms on initial load, simple as that. No graphics needed to.Now if the oil system has flow/press restriction problems, the oil temp would raise a lot from rpm alone. Check restriction.


You're thinking of heat generated by friction, but in the engine we have controlled explosions happening in each cylinder every second revolution of the crank. That's the main source of heat, not the internal friction. Increase the RPM and the number of explosions also increases, therefore the heat generated also has to increase.
That is why engines have to be idled or driven at speeds where the engine RPM is low in order to cool down the oil in turbocharged engines for example.

 

[RooflessVW]

Originally Posted By: KrisZ
Originally Posted By: Pontual
Heat is a co-product of work, right. If Load is doubled, same rpms, the heat is likely to increase a lot more than a few hundred of rpms on initial load, simple as that. No graphics needed to.Now if the oil system has flow/press restriction problems, the oil temp would raise a lot from rpm alone. Check restriction.


You're thinking of heat generated by friction, but in the engine we have controlled explosions happening in each cylinder every second revolution of the crank. That's the main source of heat, not the internal friction. Increase the RPM and the number of explosions also increases, therefore the heat generated also has to increase.
That is why engines have to be idled or driven at speeds where the engine RPM is low in order to cool down the oil in turbocharged engines for example.


In a turbocharged application, it is not the oil you are cooling by "idling down." It is the bearings inside the turbo itself, as well as the exhaust housing and turbine. The oil is pulling heat from these sources.

Rises in oil temperature are very much related to bearing loads and speed.

 

[CT8]

Originally Posted By: skyactiv
The VW GTI in my signature is no longer under warranty. I think VW is living in the dark ages requiring approved VW oil specs to have a minimum HTHS value of 3.5. If I were to use Quaker State Ultimate Durability 5W30, would I have more wear vs using something like a VW approved oil such as Castrol Edge Titanium 0W40? I'm not doing VW's 10K OCI's as outlined in the owners manual. I have been doing 5K OCI's on my GTI.
You should know better.

 

[SilverC6]

Stay with the proper spec oil in your VW.

What you feel and want to use has no basis in fact as far as suitability for the vehicle.

But do what you want.

 

[kohnen]

Originally Posted By: skyactiv
The VW GTI in my signature is no longer under warranty. I think VW is living in the dark ages requiring approved VW oil specs to have a minimum HTHS value of 3.5.


It's a risk / benefit trade-off. The upside is you get to save a few bucks on oil. The down side is you find out the hard way that there's a good technical reason for this specification and you damage your engine.

Being an engineer myself, I know how we think. We don't levy requirements unless there's a good reason to do so.

 

[KrisZ]

Originally Posted By: rooflessVW
In a turbocharged application, it is not the oil you are cooling by "idling down." It is the bearings inside the turbo itself, as well as the exhaust housing and turbine. The oil is pulling heat from these sources.

Rises in oil temperature are very much related to bearing loads and speed.


The oil isn't going to pull much heat from the whole turbocharger when it only touches the shaft. Idling does cool down the oil, and the turbo will radiate the heat away since at idle it develops 0 boost. The only role the oil has is to keep flowing through the hot shaft until it cools down. Otherwise, with stopped oil flow, it can start developing deposits on the shaft.

My minivan has the oil temperature gauge that seems to read quite well, and I noticed too the same oil temp behavior as Shannow. I could be traveling at 100kph in top gear at 1500 RPM and the oil temp will read about 85C. drop few gears to about 3500-4000 RPM and very shortly the temp will go to 95C, go back to the top gear and the temp goes back down to about 85C all while maintaining 100kph.
And actually in lower gears the engine will have less load than in the top gear because of the torque multiplier.

Edit:

When we're talking about load, as in throttle opening, then yes, more throttle, even at the same speed and RPM will increase the oil temperature, but that's because the engine is dumping more fuel not because there is more load. If the throttle remained in the same position, allowing the vehicle to slow down, like going up a hill, the fuel trim remains the same and the oil temp will remain the same as well.

Again, the main source of heat in the engine, in the oil and in the whole system is the combustion process.

 

[Pontual]

Originally Posted By: KrisZ
Originally Posted By: Pontual
Heat is a co-product of work, right. If Load is doubled, same rpms, the heat is likely to increase a lot more than a few hundred of rpms on initial load, simple as that. No graphics needed to.Now if the oil system has flow/press restriction problems, the oil temp would raise a lot from rpm alone. Check restriction.


You're thinking of heat generated by friction, but in the engine we have controlled explosions happening in each cylinder every second revolution of the crank. That's the main source of heat, not the internal friction. Increase the RPM and the number of explosions also increases, therefore the heat generated also has to increase.
That is why engines have to be idled or driven at speeds where the engine RPM is low in order to cool down the oil in turbocharged engines for example.


Nope. I think in terms of job, work, power. Not friction. Each explosion at WOT climbing a hill at 60mph in 3rd gear @ 5k rpms generates hundreds of times more Btus per second at piston bottom and cylinder liners (contacts oil), than revving at 6k rpms in neutral. Simple as that.