50w Syntec vs 50w Mobil 1, my mechanic says M1 burns off faster directly compared

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Aug 12, 2003
Tonite, while I was human ballast during my alignment, I was discussing oils with my Bosch mechanic. I was telling him about the new imported 0w-30 Syntec and some general oil discussion since he is still putting dino Castrol GTX 15w-40 in my Mom's car. Those race guys want even higher weight oil, they think they need 50w to protect their car, I dunno why, the engines were designed for 40w. Anyway, he does not like Mobil 1, he lost the front of his S6 camshaft and had a 944T with a blown engine right there in the shop, Mobil 1 products were visible in the rear hatch area. He went on to say his friend's (old) BMW burns only .5q/3000miles with Syntec 5w-50 and 1q/1000miles Mobil 1 15w-50 switching back and forth for comparison. FTR-these guys change every 2000-3000 miles. Sure, Syntec probally thickens up like STP at temp, but some people claim engine failures on M1 are common. Ironicly, people use the 50w to *protect* their engines! He uses Valvoline strait 50w Race for himself and for us, just change it often with a decent oil and forget long intervals. Man is he in the stone age, his tech was standing there telling him about the RS6 needing $30q oil only every 60,000 kilometers. Whatever, I am sending some Rotella T Synth 5w-40 up there for my Mom's Passat 2.0 [ August 21, 2003, 12:12 AM: Message edited by: TSoA ]
You cover a lot of ideas in the post. I can understand the excitement but where is the Castrol vs Mobil question and whats your opinion?
[Roll Eyes] Lets not forget that Mobil 1 is the most popular synthetic sold on the market so we will here more complaints then some of the others. Mobil's NOAK volatitliy numbers are better then Castrol so I really don't know why this happend.
The reason why is higher viscosity oils result in thicker oil film on the metal parts.
Originally posted by TSoA: Those race guys want even higher weight oil, they think they need 50w to protect their car, I dunno why,
Yea, you have to watch which oils you use with heavly loaded valve trains such as with engines in race vehicles. Those guys are likely building their engines with around .003" rod and main clearance, and perhaps up to .007" or 8 on the pistons. With grocery-getter engines, use grocery-getter engine oils. I've seen the pre tri-syn 15w50 handle some pretty high loads at some smokin' hot engine temperatures. "There goes the cam" I thought, but nope. Was it the PAOs or the additive package? Only your camshaft knows for sure. Straight SAE 50 in a BBC with 1.8 rockers, a flat tappet cam, .690" lift, and 550 lb springs? No, I think I'll use SL GF-3 5W20.
"where is the Castrol vs Mobil question and whats your opinion?" My point is to convey that his customer actually went back and forth between 5w-50 Syntec and Mobil 1 15w-50 with consistant resulys, the M1 burned off rapidly as others have reported. Blown engines, LL oils, VW 2.0l oiling requirements, they are all included in the post for flavor. M1 is a light 50w oil anyway, I guess that explains it.
When I used Syntec 5W-50 I never had to add any oil between oil changes (every 10k miles). I can't speak for the M1 15W-50, because I haven't used it, but I do need definitley more M1 0W-40 than Syntec 5W-50. Of course, the car is older now...
Originally posted by moribundman: When I used Syntec 5W-50 I never had to add any oil between oil changes (every 10k miles). I can't speak for the M1 15W-50, because I haven't used it, but I do need definitley more M1 0W-40 than Syntec 5W-50. Of course, the car is older now...
I run Mobil1 15w50 in my motorcycle which is a 750cc V-4 with 4 chain driven cams, 11:1 compression and revs to over 10,000 RPM with a shared sump for tranny & wet clutch. The oil does not burn off and stays at the same level on the dipstick for at least 5,000 miles (still running based on UOA results).
My experience too. M-1 15-50 burned off twice as much as Syntec 5-50. And, no the 15-50 is NOT thinner by any means....IMHO, goes to show the quality of M-1...cheap PAO's...cheap addative package...however, it's just another flavor of OTC synthetic....readily avail. for ~$4-5/qt. at your local and neighborly Wal-Mart. You pick the flavor...
Hi,I noted with Syntec 5w-50 about 1/2 qt loss in 5k miles('99 Ford Van). With Delvac-1(5w-40) there was no loss in 5K miles! [Cool]
I have never had M1 15W50 burn off! I ran it in amoung other things a 22RE that i blue printed for raceing. It redlined ( see valve float) at 10,000 RPM's I never had a problem with burn off and this was well before trisyn or SuperSyn. My Dad runs 15W50 almost year round in one truck and on occassion he has ran it year round. He runs 15W50 in another new truck until snow flys. Neither vechile burns a drop of oil! I must also say that I have not had a problem with M1 10W30 burning off either in daily driver use.
John, it seems like your cars just don't burn oil! If you take an oil consuming engine as a starting point, then the results might consistant with this report. It's a direct comparison, a rarity here, that's why I posted it.
TSOA, I have had vechiles burn oil. The three oils I have had burn off issues with were non synthetic 10W30. They were Esso,Exxon and Mobil Drice Clean. In each case when I returned to Mobil 1 10W30 or 15W50 the oil consuption stoped or reduced to more apropreiate level. Drive Clean was the worst. In a vechile that previously used no oil between oil changes it consumed 3 quarts in 3000 miles. I drained the oil out bent back to M1 and the problem stoped. In college I tried to save a few bucks on oil and it bit me in the rear. [ August 24, 2003, 09:57 PM: Message edited by: JohnBrowning ]
Drive Clean blows. I put it into Mom's 12v Audi, a notorious oil consumer, it used 1q every 1000 miles! With SynPower it hardly used any over a 6000 interval, maybe <1q total. I choose DC oil because of the prestige associated w/ M1, a mistake. SynPower was a mistake in hindsight too. [ August 24, 2003, 11:18 PM: Message edited by: TSoA ]
I've used M1 10w-30 and had zero consumption problems. Amsoil 10w-30 was good too. M1 15w-50 is a great oil and should have zero burn off issues. [ August 24, 2003, 11:13 PM: Message edited by: buster ]
no offense to anyone on this board who may be an auto mechanic, but IMO an opinion from an auto mechanic on what oil is "best or better" isnt worth much. Most of these statements you will hear come from anectdotal evidence, such as " well I had a customers car that blew up which used Mobi1 oil" , or "my pickup truck has 500,000 miles on it using Castrol GTX and its the best oil you can buy", etc....... . If you look at the signs of most mechanic shops you will likely see an oil endorsement picture on that sign, that's how Valvoline convinced us that more mechanics in the U.S. use their oil over all other oils. Personally I would trust my $14.00 oil analysis report more than any mechanic that I've ever met. I actually had one mechanic tell me that 5w-20 oil is thicker than 5w-30 oil, so I don't think they are that knowledgeable on oil chemistry. Just my opinion, not trying to flame anyone. Joey
[Smile] You guys are saying "no, no, no". I believe my mechanic, "why, why, why?" is the question. M1 15w-50 is a light 50w, maybe the Syntec holds grade better.
My (former) mechanic, who's been in the business for over 40 years knew about as many wives tales about oil as the next guy. "You must never go back after using synthetic oil!" "It's not possible that your car doesn't need oil added between oil changes." "That oil leak is from using synthetic oil!" And so on and so forth... [Razz] [ August 24, 2003, 11:43 PM: Message edited by: moribundman ]
Too bad, dude. My Bosch mechanic has been Audi-certified for 20 years, his dad a Master BMW mechanic for over 35 years, they are originally from Portugal. "John" has a Solo race licence, I've been on Watkins Glenn track with him at a Porsche Club event. He is often referenced by dealerships as his father-in-law is a Service Manager and even on AudiWorld he is known for his work.(keyword:Woodlawn) What I am most impressed by is him working with Garett on cracking the Motronic-5 codes, ultimately finding the returnless fueling solution which held up (APR) chips for the B6 (8E) platform cars. The latest there is serial programming, a flash-to-oem upgrade. Anyway, I do implicitly trust him. I *remain* his best-informed customer though, he would not even HAVE an oil conversation with another customer. [ August 25, 2003, 12:02 AM: Message edited by: TSoA ]
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