| root | 05-05-2005 11:59 AM |
Mobil 1 0W-40 for daily driver + occasional track day, yes/no/maybe so?
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I'm about to change my STi' oil for an upcoming track day and am trying to decide what to put in. I currently have M1 5W-30 in it, but some of the things I've been reading lately scare me into thinking that is too thin for extended high RPM usage. I also live in central Florida where it almost never drops below freezing even during mid-winter.
Anyone think Mobil 0W-40 would be too thick for my needs? What about mixing 5W-30 (or 0W-30) with 0W-40 in a fifty/fifty mixture for a pseudo 0W-35? Is that a no-no?
Thoughts, comments, suggestions?
I don't mind changing the oil a little more frequently or specifically before and after the track day if I need to. Engine protection is goal number one.
Anyone think Mobil 0W-40 would be too thick for my needs? What about mixing 5W-30 (or 0W-30) with 0W-40 in a fifty/fifty mixture for a pseudo 0W-35? Is that a no-no?
Thoughts, comments, suggestions?
I don't mind changing the oil a little more frequently or specifically before and after the track day if I need to. Engine protection is goal number one.
| kfoote | 05-05-2005 12:23 PM |
IMO, there's no reason to switch from the M1 5w30, I'd just reccommend a more frequent oil change interval if you're doing a track day. If you figure 1 hr track time = 1000 street miles, you'll be plenty safe.
| zzyzx | 05-05-2005 02:15 PM |
There are (at least) three reasons to use a higher viscosity oil on the track:
1) Heat. Sustained higher than normal temp leads to a thinning of the oil (lower viscosity).
2) Higher sustained RPMs. Higher viscosity oil will protect bearings better than a similar lower viscosity oil at higer RPMs.
3) G-loading. High lateral Gs, combined with high RPMs will evacuate the oil from the pan and tend to pool it in the heads on our Subarus. This leaves the bottom end at risk. Specifically, rod bearings. A higher viscosity oil with better film strength will do a better job of protecting your rod bearings.
1) Heat. Sustained higher than normal temp leads to a thinning of the oil (lower viscosity).
2) Higher sustained RPMs. Higher viscosity oil will protect bearings better than a similar lower viscosity oil at higer RPMs.
3) G-loading. High lateral Gs, combined with high RPMs will evacuate the oil from the pan and tend to pool it in the heads on our Subarus. This leaves the bottom end at risk. Specifically, rod bearings. A higher viscosity oil with better film strength will do a better job of protecting your rod bearings.
| root | 05-05-2005 02:26 PM |
So, zzyzx, I assume that means if you were me you would use the M1 0W-40 over M1 5W-30? Or something else?
| MarkA | 05-05-2005 02:27 PM |
Or, switch to a "thicker" 5W-30 such as Redline.
| zzyzx | 05-05-2005 02:29 PM |
Absolutely. As to the relative merits of each brand of oil, that a whole 'nother ball of wax. For the track, I'd stick to an oil with an upper range of 40-50. I use Motul 300V 15-50, but it's a dedicated race car... (read: expensive stuff)
| kfoote | 05-05-2005 02:54 PM |
[QUOTE=zzyzx]There are (at least) three reasons to use a higher viscosity oil on the track:
1) Heat. Sustained higher than normal temp leads to a thinning of the oil (lower viscosity).
2) Higher sustained RPMs. Higher viscosity oil will protect bearings better than a similar lower viscosity oil at higer RPMs.
3) G-loading. High lateral Gs, combined with high RPMs will evacuate the oil from the pan and tend to pool it in the heads on our Subarus. This leaves the bottom end at risk. Specifically, rod bearings. A higher viscosity oil with better film strength will do a better job of protecting your rod bearings.[/QUOTE]
5 years ago, I would agree with you, and technically, you are correct. That having been said, the film strength of Mobil 1 5W30 is plenty strong enough to leave a residual film on the rod bearings. The rod bearing issue tends to occur in very long, high g-loading corners, and where it would be an issue with Mobil 1 5W30 it would also be an issue with M1 15W50. The trend in manufacturers has been to go with lighter weight oils because of the improvement in the chemistry of off the shelf non-synthetic oils, better manufacturing techniques that use less clearance on bearing surfaces, and the benefits that using lighter oils have, namely better protection at initial startup and lower internal engine drag, which increases efficiency, power, and fuel mileage.
Again, for a track only car that is > 5 years old I agree, but for a car that's designed to use a lighter weight oil and is primarily a street car, it's not really necessarry.
<--- Runs Pennzoil 5W30 synthetic in street STi and track only 1999 Miata, which does have bottom end oiling issues, and has never had a problem with either.
1) Heat. Sustained higher than normal temp leads to a thinning of the oil (lower viscosity).
2) Higher sustained RPMs. Higher viscosity oil will protect bearings better than a similar lower viscosity oil at higer RPMs.
3) G-loading. High lateral Gs, combined with high RPMs will evacuate the oil from the pan and tend to pool it in the heads on our Subarus. This leaves the bottom end at risk. Specifically, rod bearings. A higher viscosity oil with better film strength will do a better job of protecting your rod bearings.[/QUOTE]
5 years ago, I would agree with you, and technically, you are correct. That having been said, the film strength of Mobil 1 5W30 is plenty strong enough to leave a residual film on the rod bearings. The rod bearing issue tends to occur in very long, high g-loading corners, and where it would be an issue with Mobil 1 5W30 it would also be an issue with M1 15W50. The trend in manufacturers has been to go with lighter weight oils because of the improvement in the chemistry of off the shelf non-synthetic oils, better manufacturing techniques that use less clearance on bearing surfaces, and the benefits that using lighter oils have, namely better protection at initial startup and lower internal engine drag, which increases efficiency, power, and fuel mileage.
Again, for a track only car that is > 5 years old I agree, but for a car that's designed to use a lighter weight oil and is primarily a street car, it's not really necessarry.
<--- Runs Pennzoil 5W30 synthetic in street STi and track only 1999 Miata, which does have bottom end oiling issues, and has never had a problem with either.
| zzyzx | 05-05-2005 03:12 PM |
... sounds like a guy that's never spun a rod bearing in a Subaru on the track. Am I correct?
| ranger5oh | 05-05-2005 03:25 PM |
Im running 0W40 no problems :)
| kfoote | 05-05-2005 03:42 PM |
[QUOTE=zzyzx]... sounds like a guy that's never spun a rod bearing in a Subaru on the track. Am I correct?[/QUOTE]
Not in a Subaru, but I have twice in a Porsche 944 (on track), and seen it happen a couple of times in Miatas I've worked on (also on track). In the 944 it was with Mobil 1 15W50 and in the Miatas in two cases it was 15W50 non-synthetic, and in the other two it was 5-30 synthetic. In the Miatas, the issues were all eventually traced to oil starvation in the bearings due to not having enough oil in general in the engine. The 944 was an inherent problem that was more the function of a 160k mile engine than anything else the first time, and an improperly machined crankshaft after.
Not in a Subaru, but I have twice in a Porsche 944 (on track), and seen it happen a couple of times in Miatas I've worked on (also on track). In the 944 it was with Mobil 1 15W50 and in the Miatas in two cases it was 15W50 non-synthetic, and in the other two it was 5-30 synthetic. In the Miatas, the issues were all eventually traced to oil starvation in the bearings due to not having enough oil in general in the engine. The 944 was an inherent problem that was more the function of a 160k mile engine than anything else the first time, and an improperly machined crankshaft after.
| root | 05-05-2005 03:46 PM |
Anyone use or have thoughts M1 Racing 0W-30? I guess that would another option as it should offer better wear protection than the other M1 '30s but still be thinner than the 0W-40. I imagine it would need to be changed very frequently though, but I have no idea how frequently. Enough for 1000 street miles + 2-4 hours of track time?
| zzyzx | 05-05-2005 04:03 PM |
[QUOTE=kfoote]Not in a Subaru, but I have twice in a Porsche 944 (on track), and seen it happen a couple of times in Miatas I've worked on (also on track).[/QUOTE]
Well, our Subarus typically have poor bearing tolerances from the factory. They are [b]not[/b] matched for tolerances like, say, Hondas are. Some come a little too tight, some a little too loose. It's the tight ones that tend to go bad. Either way, it's a known issue in Subarus and IMO a higher viscosity oil is cheap insurance with little to no downside. The real fix would be something more along the lines of an Accusump, however.
root - There are about eleventy billion threads on the relative merits of different oil brands on here. Honestly, in having read most of them and discussed this issue at length with many people, I think you'll be fine with the Mobil 1 0-40. If you really want to learn about oils, read up some and do regular oil analyses via Blackstone Labs or some other company. If you do this regularly, you'll know exactly what's happening in terms of wear in your engine.
Well, our Subarus typically have poor bearing tolerances from the factory. They are [b]not[/b] matched for tolerances like, say, Hondas are. Some come a little too tight, some a little too loose. It's the tight ones that tend to go bad. Either way, it's a known issue in Subarus and IMO a higher viscosity oil is cheap insurance with little to no downside. The real fix would be something more along the lines of an Accusump, however.
root - There are about eleventy billion threads on the relative merits of different oil brands on here. Honestly, in having read most of them and discussed this issue at length with many people, I think you'll be fine with the Mobil 1 0-40. If you really want to learn about oils, read up some and do regular oil analyses via Blackstone Labs or some other company. If you do this regularly, you'll know exactly what's happening in terms of wear in your engine.
| root | 05-05-2005 07:17 PM |
Thanks. I think I will probably go with 0W-40, at least for the my track sessions. I do plan to send my current oil to Blackstone and will send my after track oil.
All these blown motor stories have me scared. :) Rather not rebuild the engine for another few years.
All these blown motor stories have me scared. :) Rather not rebuild the engine for another few years.
| mnavarro | 05-05-2005 08:26 PM |
Dude, you should also seriously consider oil cooler. If I was tracking my car that's what I would get and run 0wt40.
| makofoto | 05-05-2005 09:59 PM |
A number of Corvette racers use 0/20 Silkelene racing oil ... $100 for an oil change worth of oil ... that doesn't last very long ... but supposedly can give 5% more hp ?
| BIGSKYWRX | 06-05-2005 10:10 PM |
I run 5W40 Motul during the summer (track days)- there is a good thread (older) that deals directly w/ track days and oil testing ( I had mine submitted, as did several others).
cliff notes- M1 15W50 probably great for many cars, the WRX isn't one of them.
M1 0W40 I'd be interested on how it tests out- it's cheaper than the Motul I'm buying :)
cliff notes- M1 15W50 probably great for many cars, the WRX isn't one of them.
M1 0W40 I'd be interested on how it tests out- it's cheaper than the Motul I'm buying :)
| MRF582 | 06-05-2005 11:37 PM |
I used M1 15W-50 for one oil change during summer of last year. then changed to M1 5W-30 for the winter. i'm due for another oil change now and wondering why you guys don't recommend 15W-50. i do autoX. and did a track day yesterday.
| drees | 06-05-2005 11:38 PM |
[QUOTE=zzyzx]Well, our Subarus typically have poor bearing tolerances from the factory. They are [b]not[/b] matched for tolerances like, say, Hondas are. Some come a little too tight, some a little too loose. It's the tight ones that tend to go bad. Either way, it's a known issue in Subarus and IMO a higher viscosity oil is cheap insurance with little to no downside. The real fix would be something more along the lines of an Accusump, however.[/QUOTE]I find it interesting that you say that it's the tighter bearings are the ones that fail and then recommend a thicker oil... conventional logic says that for tighter bearing clearances you want to run thinner oil.
Either way, make sure that you keep the dipstick reading slightly over full and you shouldn't have any problems. Keep an extra quart or two with you and check it before each session and before driving home.
Either way, make sure that you keep the dipstick reading slightly over full and you shouldn't have any problems. Keep an extra quart or two with you and check it before each session and before driving home.
| makofoto | 06-06-2005 02:16 AM |
so many conflicting suggestions ... ?!
I hear thick oil is better for turbo lubing ...
I hear thin oil is better because of less friction, more power for racing (I have a friend that was using 0/20 Silkolene that cost over $100 just for the oil for an Z-06 oil change! He used it for 13 AX runs and then dumped it. He was scared that it sacrificed to many protective qualities. Silkolene later told him it was good for AT LEAST 500 miles. :-)
I hear "keep lots of oil in the engine" ...
I hear "Use just enough oil so the oil warning light doesn't come on ... :-)
Seems like 5/30 Mobil 1 ... measuring full after a few minutes at stand still is a good compromise! :-) ... but of course only change to Mobil 1 after 5,000 miles of "breaking in." Because it's too slippery for proper breaking in ... although a lot of very high end sports cars come with Mobil 1 ?!
I hear thick oil is better for turbo lubing ...
I hear thin oil is better because of less friction, more power for racing (I have a friend that was using 0/20 Silkolene that cost over $100 just for the oil for an Z-06 oil change! He used it for 13 AX runs and then dumped it. He was scared that it sacrificed to many protective qualities. Silkolene later told him it was good for AT LEAST 500 miles. :-)
I hear "keep lots of oil in the engine" ...
I hear "Use just enough oil so the oil warning light doesn't come on ... :-)
Seems like 5/30 Mobil 1 ... measuring full after a few minutes at stand still is a good compromise! :-) ... but of course only change to Mobil 1 after 5,000 miles of "breaking in." Because it's too slippery for proper breaking in ... although a lot of very high end sports cars come with Mobil 1 ?!
| root | 06-06-2005 08:25 AM |
I ran Mobil 1 Racing 0W-30 at the track last weekend + highway to and from track + a little around town driving. Totalling about 1000 miles + track time. I'm going to change it this week and send some off for testing. Should be interesting.
| makofoto | 06-06-2005 12:02 PM |
I had 5/30 Mobil 1 and 15/50 "race" Mobil 1 tested after using each about 3,000 miles, including a lot of Auto Cross ... and both came back with virtually identical excellent results ...
| GarySheehan | 06-06-2005 01:00 PM |
The technicians at Subaru HQ in Cherryhill, NJ suggested that we use 20W50 in our WRX race car. We used RedLine 20W50 exclusively. I don't believe RedLine is API certified, so to keep your engine under warranty, M1 15W50 may be a better choice.
Gary
Sheehan Motor Racing
[url]www.teamSMR.com[/url]
Gary
Sheehan Motor Racing
[url]www.teamSMR.com[/url]
| subenerd | 06-06-2005 01:49 PM |
I thought redline had all the qualifications that was needed outlined by the owners manual, it just isnt 'energy conserving' Why isnt it API certified? Energy conservation?
Ive been using it exclusivly since 3750 miles and currently have 39K on the odometer. No mechanical issues yet...hope I dont **** up my engine
Ive been using it exclusivly since 3750 miles and currently have 39K on the odometer. No mechanical issues yet...hope I dont **** up my engine
| jmlmr2 | 06-06-2005 01:51 PM |
Hopefully you will be able to find M1 0W-40...in my parts it is getting hard to come by. Check the data sheets on M1 0W-40 vs. the other M1 oils and you will see that it is a different animal with regard to vital oil stats - for example, you can almost draw a trendline through the cST measurements for 5W-30, 10W-30, and 15W-50 M1, but the 0W40 doesn't really fit on that line...the formulation must be different somewhere. Also note that the 0W-40 is the "european" grade, with Porsche, MB, and VW approvals that the other grades of M1 don't have (not that those approvals really mean anything for our cars, just that the oil must be "different" in some way if 0W-40 gets the approval and the other grades don't). Another good alternative (if you can find it) is "German Castrol" 0W-30. Very similar stats to M1 0W-40, and also with Porsche, MB, VW approval. Plus, the Castrol is green and smells like gummi bears ;)
With that said, with short change intervals, most anything would probably be safe for the engine, with the synthetics offering better high-temp protection than dino.
With that said, with short change intervals, most anything would probably be safe for the engine, with the synthetics offering better high-temp protection than dino.
| root | 06-06-2005 01:56 PM |
I almost put in the M1 0W-40 before the track day, but ended up going for the Racing 0W-30 because it supposedly has a higher level of anti-wear additives. Not that I know if that really does anything. I'm a fool for marketing. :) I can get M1 0W-40 at the local Discount Autoparts. I may still give it a try.
| ToddStratton | 06-06-2005 02:59 PM |
I've been using M1 0w40 for two years in my STi. It lives a pretty rough life now, triple digit cruise to the track, then long, hot laps. I add about 1/2 qt per 3K miles. The car is stock drivetrain-wise.
I may play with some of the other recommended SAE viscosities for "severe driving conditions" (per the manual) like 10w50, 20w40, 20w50. Unfortunately, buying synthetic oil on the economy is outrageous here. We're talking $20 for a liter. M1 is cheap on base though.
TRS
I may play with some of the other recommended SAE viscosities for "severe driving conditions" (per the manual) like 10w50, 20w40, 20w50. Unfortunately, buying synthetic oil on the economy is outrageous here. We're talking $20 for a liter. M1 is cheap on base though.
TRS
| BIGSKYWRX | 06-06-2005 09:41 PM |
The results for the 15W50 didn't look good- a fair amount of wear being indicated, the fellow switched to 5W30 and things looked much better.
It might be a function of pretty tight tolerances by Subaru (??), but the thicker oil (at least in the testing I saw) didn't appear to be the best choice.
[url]http://forums.nasioc.com/forums/showthread.php?t=375446[/url]
The WRC car interestingly runs Motul 5W40- looks like I'm in pretty good company :)
It might be a function of pretty tight tolerances by Subaru (??), but the thicker oil (at least in the testing I saw) didn't appear to be the best choice.
[url]http://forums.nasioc.com/forums/showthread.php?t=375446[/url]
The WRC car interestingly runs Motul 5W40- looks like I'm in pretty good company :)
| root | 06-07-2005 08:16 AM |
Yeah. I don't think I could be talked into 50 oil. 40 probably, but not 50. What good is the oil going to do if it is too thick to work its way in between those critical pieces.
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