GTX 20W50, 3,355mi, 126k, '84 BMW 325e 2.7L

[74Scout]

Vehicle: 1984 BMW 325e (E30) Engine: 2.7L I6 (M20B27) Vehicle Mileage: 125,868mi OCI mileage: 3,355 miles Oil: Castrol GTX 20W-50 (5 quarts) Oil Filter: Bosch Make up oil: none Driving conditions: ~85/15 (Highway/City) Refilled: Shell Rotella T6 5W-40 My thoughts: Other than the Copper showing above average, the others seem to be good. I am not too worried about the silicon as I had replaced the valve cover and oil pan gasket, and this is 2nd fill after it was replaced. Also, the silicon levels aren't that much higher than what is reported on my Toyotas. I think it is worth noting that Blackstone says the Universal Averages are based on 3,200mi of use. I was a little worried about fuel dilution as it seems to run a tad rich, and sometimes I think I can smell a hint of gas when I am checking the oil. I am glad the report showed low fuel dilution. I am looking to extend the OCI, so I can just rack up the miles on this commuter, so I settled on the Shell Rotella T6 5W-40. It seems to be one of the synthetics preferred over on the E30 forums, and I will see how it goes. I picked up some on sale. I am also considering Castrol Edge 0W-40 as the 5qt jug is similarly priced. If anyone has other recommendations, let me know. I am not really interested in Amsoil or Redline at this time, as I would like to be able to find the oil at the local parts store/WM. Backstory: This is my first UOA on this vehicle. I purchased it back in May and have put almost 7k miles on it commuting across Houston (~120mi/day). I had done 4 previous OCs in the 1st 3500miles to help clean up the motor, and I was troubleshooting a cracked oil pan from a rear-end collision. The 1st OC was right when I got the car home after I bought it, and the 2nd drain was to remove the fluorescent dye I used to find the crack in the oil pan to fight with the guy's insurance (hit me 1 week after I bought it). The 3rd was when I drained it to patch the crack with aluminum tape until my replacement pan came in, and the 4th was when I installed the new pan. All the oil I had used so far has been Castrol GTX 20W50, and looks like from the window sticker, the PO used whatever 5W30 was available at the local lube shop.

 

[Lolvoguy]

Congrats on the purchase. Those eta motors are mileage monsters! My first BMW was a very similar 1986 325es with manual transmission. That thing was unstoppable once at highway speed and would cruise efficiently at 70 mph Just remember to stay on top of timing belt changes and it'll reward you with many years of efficient motoring. Also, you sure you wouldn't rather go with Rotella T 15w40 in your climate? IIRC that oil has a bit more moly for our applications. It's also cheaper considering the frequency of OCI's your doing

 

[vitez]

BMW specs 15W-40 for anything above 5°F for your engine. I'd use any HDEO in that grade. You could probably run it to a 5000 mile OCI with your easy highway use.

 

[CT8]

The BMW three and a quarters with the ETA are really nice cars.

 

[jayg]

Originally Posted By: vitez

BMW specs 15W-40 for anything above 5°F for your engine. I'd use any HDEO in that grade. You could probably run it to a 5000 mile OCI with your easy highway use.

Especially in Houston, I'd run Maxlife HDD 15w40 at 5k changes with no worries.

 

[zeng]

This used 20W50 is still robust , OCI could've been extended to say , 5K miles.

 

[74Scout]

Yeah, the 20W50 looks like it could go farther. I did the analysis on the oil I drained so I couldn't run it any longer. I was trying to find a synthetic so I could work towards longer drain intervals when compared to a conventional oil. I wasn't aware of any 15W40 HDEO synthetics, so that was why I went with the Rotella T6 5W40. Does the 5W really make that significant of a difference in the viscosity of the 40 grade while at operating temperature when compared to a 15W40? Worst case scenario, the T6 5W40 is still better than the jiffy lube 5W30 the PO had used it for no telling how many OCs. I'm already 2k miles into this run with the T6 after only 3 weeks, so it won't be long before it gets drained and sent for testing. I'm planning on doing 5k miles. I have noticed a slight increase in consumption when compared to the 20W50 (a 3/16" drop in 2k mi vs 1/8" drop in 3.5k mi), but I was expecting that might happen.

 

[aquariuscsm]

Have you ever tried M1 15W50? I hear about alot of BMW owners using it.

 

[kschachn]

Originally Posted By: aquariuscsm

Have you ever tried M1 15W50? I hear about a lot of BMW owners using it.

You do? A lot? I've never heard of one but maybe that's just me

 

[B320i]

Always great to see a UOA from an older Bimmer! Just remember, the "Oil Life Monitor" fitted to these supposedly does a 7,500 mile interval... Not sure how that would've went with 1980's mineral oils, then again, BMW spec'd 20w50 or 15w40 "Heavy Duty" oils for these cars. The old I6 isn't very hard on the oil, with a big sump and fairly 'lazy' engine. With long highway runs, less cold-starts and Texas weather, you can probably get away with GTX for at least 5,000 miles, if not the interval specified by your OLM. Seeing as you've switched to Rotella T6, try and get a dipstick pump and take a sample and keep driving at 5,000. My opinion will be that 7,500 will be easily attainable with a good synthetic, or even mineral HDEO. Obviously, this post could well get me shouted at my the vintage BMW crowd...

 

[74Scout]

I've heard some about the M1 15W50, and M1 5W50 over on the forums. From what I've found, the common recommendations seems to be: 1. Castrol GTX 20W50 ("hot" climate) 2. 10W40 (moderate/winter climate) 3. HDEO 15W40 (Moar Zinc for my baby) 4. Synthetics: M1 15W50, M1 5W50, Castrol Edge 5W50, T6 5W40, Delo LE 5W40, and others. Most say the synthetic PCMO xxW40 are too "noisy" for their preference, and don't meet the temperature chart in the manual. Synthetics don't seem to get a lot of love over on the E30 forums, since most like to change their oil at 3 or 5k mi, well before the 7.5k mi Oil Life monitor. When I picked up the T6, I didn't see the 5qt jugs of M1 15W50 at the WM. They must have been out then, but now I see it on the shelf for ~$26. Honestly, I expected the GTX 20W50 to probably last at least the 5k miles, and am looking for synthetic for under $30 (5qts) to go 10k+ miles. Otherwise, the synthetic isn't cost effective. I was also looking for an oil with a lower xxW for "better" startup protection. Using that criteria, the main candidates were the synthetic HDEOs, and I picked the T6 b/c I can find single quarts of it to round out my 5 qt change. I wasn't able to find single qts of the synthetic Delo. However, now that I found the 5qt jug of the M1 15W50, I may try that once I finish my T6 runs and compromise with only a slightly lower xW but have the benefit of a synthetic.

 

[Garak]

Originally Posted By: 74Scout

Most say the synthetic PCMO xxW40 are too "noisy" for their preference, and don't meet the temperature chart in the manual.

Do note that given the vintage of your vehicle, SAE J300 was different at the time, and a multigrade 40 could have had a significantly lower HTHS than a modern multigrade 40.

 

[alarmguy]

Castrol 20/50 looks good for you in your Southern Climate, if you do go 5/40 just be sure to check the oil level after 2k miles just as a precaution since you only used a conv 20/50 before. I agree with the others as far as if BMW recommends 15/40. Seems like you have a good engine there!

 

[74Scout]

Originally Posted By: Garak

Originally Posted By: 74Scout

Most say the synthetic PCMO xxW40 are too "noisy" for their preference, and don't meet the temperature chart in the manual.

Do note that given the vintage of your vehicle, SAE J300 was different at the time, and a multigrade 40 could have had a significantly lower HTHS than a modern multigrade 40.

I figured that the with the changes over the last 30 years, that some aspects of that temperature chart in the manual may not be directly applicable with the current Oil/Viscosity specs. That's why I felt it was OK to try the T6. However, I would have thought that the older multigrade 40s would have had higher HTHS than a modern multigrade 40, as from what I can find in the recent years the HTHS has decreased in pursuit of better fuel economy/emissions. My knowledge of this is limited, as this BMW has been around a couple years more than I have, and I have been learning about the different aspects of oil for only a year or two. It would be interesting to know what the HTHS rating was for the various multigrade oils listed in the E30 manual.

 

[Garak]

Some of the dated 10w-40 examples were terrible, and had to have no higher HTHS than an ILSAC 30. An old SAE 40 monograde would have probably had decent HTHS, and probably most 15w-40 examples back then, too. But, the HTHS rules have tightened up. While we see HTHS drop within certain grades, or, more accurately, cluster around the low end for ILSAC grades, the tightening of HTHS limits for 40 grades has seen some rise from back then. And, most of the relevant specifications for such grades (i.e. CJ-4 or any of the ACEA or European OEM approvals) require an HTHS of 3.5 or higher anyhow. With a vehicle like yours, assuming there are no other issues one must take into consideration (i.e. leaking or consumption), one could easily run a 5w-40 or 0w-40 HDEO year round. Any modern A3/B4 LL-01 type lubricant would also be suitable year round, be it a 0w-30, 5w-30, 0w-40, 5w-40, or what have you, given that it will have the minimum HTHS of 3.5 or higher. If leaking or consumption or costs were a concern, and it were mine, and I were living in your climate, I'd simply run a 15w-40 year round.

 

[4WD]

Garak: With the Rotel craze - you seem to be one of the few Mobil Delvac gurus: I just bought current Delvac 1300 15w40 on sale. Has a pretty strong HTHS. Will it drop when the new versions take over the shelves ?

 

[kschachn]

All older BMWs are back-specified to Longlife-01, correct? At least mine is, and I am going to guess the E30 is as well. LL-01 oils render the temperature and viscosity chart irrelevant, why not just use Castrol 0W-40? It's cheap, easily available and works in any climate - TX included.

 

[Garak]

I doubt the HTHS will change, at least on a product like the 15w-40. There would really be no reason for it to change, at least that I could see. There are alternative grades to choose from, for those who really want to fine tune HTHS. Realistically, there is still room to move with a 15w-40 in SAE J300. However, I've not seen a lot of evidence that the oil companies have been doing so, even to promote fuel economy. They simply push things like 5w-40, 10w-30, and 5w-30 HDEOs, which are simply a more effective way to do that.