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Discussion Starter #1
Having just recently had my car serviced, well about 1000 miles or so ago, I though I'd enquire as to which type/grade of oil they used. My reason for this was that I had noticed that I had not required to top up yet, and prior to this service I found that I was topping up about 1L for 800-1000 miles.

I normally top up with Castrol Magnatec 15w40...

I was VERY surprised when the delar said it was 5w40 Fully Synthetic and he did stress that it must be synthetic.

My initial thoughts were to stick to what I had been using, I also think that the handbook mentiones 15w40 / 15w50

Thoughts and comments please...
 

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Plisken, I have it in my mind that the b38 engine is supposed to run with fully synthetic, other m engines pre 1992 are run on high quality mineral oil. I am sure there is a mention of this at bmwe34m5 web site. My latest 20w/50 f.s. has done 1900 miles and no oil request from the M brain so far. I'll check the dipstick just in case though....

cheers,
Phil.
plisken said:
Having just recently had my car serviced, well about 1000 miles or so ago, I though I'd enquire as to which type/grade of oil they used. My reason for this was that I had noticed that I had not required to top up yet, and prior to this service I found that I was topping up about 1L for 800-1000 miles.

I normally top up with Castrol Magnatec 15w40...

I was VERY surprised when the delar said it was 5w40 Fully Synthetic and he did stress that it must be synthetic.

My initial thoughts were to stick to what I had been using, I also think that the handbook mentiones 15w40 / 15w50

Thoughts and comments please...
 

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hi

i have just changed the oil in my m5 3.8 i have used 15\40 castrol gtx high mileage oil for engines over 75000
tony
 

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RS 10/60 old bean :byee55amg

700-1000 miles between top ups dependant on driving :wroom: :wroom:

also change oil between services(insp every 5-6k)
 

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Steve Mac said:
RS 10/60 old bean :byee55amg

700-1000 miles between top ups dependant on driving :wroom: :wroom:

also change oil between services(insp every 5-6k)

Munich Legends say Castrol GTX 10 -40 is OK for street use. 10 - 60 for serious track day users. Oil change every 3000 miles. I just changed mine at 3000 miles and everyone commented on how dirty the oil was. Maybe 5 to 6 k might be in the handbook but I think that would seriously shorten the life of a motor that should easily last 200k but that will cost £15k to replace.

:cheers:

ralph (vadas1)
 

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Discussion Starter #6
So should I get rid of the 5w40 that was used during the last service?

I'm totally at a loss as to what to do going forward...

I was under the impression that a fully synthetic oil should not really be used on our engines.
 

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plisken said:
So should I get rid of the 5w40 that was used during the last service?

I'm totally at a loss as to what to do going forward...

I was under the impression that a fully synthetic oil should not really be used on our engines.
If your motor is not leaking oil you are probably OK. Scotland is colder than Poole. I think your impression about not really using fully synthetic oil is probably right but I am certainly not an expert ( but some on this board are! ).

:cheers:

ralph (vadas1)
 

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No point wasting good oil plisken, unless your going to boot the crap out of your car - I dont think it matters too much whether it's mineral or synthetic as long as either is a good quality brand. From checking out the web (amsoil site) I understand the main benefit offered by synthetic oils is a greater film / shear stength - thus coating on oily bits takes a bit more to wear off and is more resitant to temperature. Given that winter has arrived I think your 5w/40 should see you through to the spring ok, due to reduced speeds and salt on the roads, the M should only be out on nice days - so you'll be lucky if you manage 5 miles.

cheers,
Phil.
plisken said:
So should I get rid of the 5w40 that was used during the last service?

I'm totally at a loss as to what to do going forward...

I was under the impression that a fully synthetic oil should not really be used on our engines.
 

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Phlem5 said:
No point wasting good oil plisken, unless your going to boot the crap out of your car - I dont think it matters too much whether it's mineral or synthetic as long as either is a good quality brand. From checking out the web (amsoil site) I understand the main benefit offered by synthetic oils is a greater film / shear stength - thus coating on oily bits takes a bit more to wear off and is more resitant to temperature. Given that winter has arrived I think your 5w/40 should see you through to the spring ok, due to reduced speeds and salt on the roads, the M should only be out on nice days - so you'll be lucky if you manage 5 miles.

cheers,
Phil.
I agree with you but didn't someone actually say that the motor has to be designed to use synthetic for it to be of any use?

:cheers:

ralph (vadas1)
 

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vadas1 said:
I agree with you but didn't someone actually say that the motor has to be designed to use synthetic for it to be of any use?

:cheers:

ralph (vadas1)
Ralph, which M5 sage said that?, the guy must know his stuff. No doubt that info was picked up from some book or other :cool: , safe to say (I hope) - a new engine should be run in on mineral before swithching to synthetic other than that you can suit yourself.
cheers,
Phil.
 

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plisken said:
I normally top up with Castrol Magnatec 15w40...

I was VERY surprised when the delar said it was 5w40 Fully Synthetic and he did stress that it must be synthetic.

Thoughts and comments please...
Castrol say E34 M engines should exclusively use the TWS 10/60 (no longer available I think, so Racing Syntec replaces it), but that would seem justified for hard driving in hot weather. The M engines are high performance power plants generating lots of heat - consider that platinum plugs are not to be used on our cars. BTW I use Split Fire plugs, definitely recommendable. But for normal driving under no extreme temperatures like we have now, a 5/40 or 10/40 synthetic oil would be fine.
I use full synthetic Magnatec for its attraction technology, as cold starts are where the engine gets most wear.
 

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Eryk_PL said:
Castrol say E34 M engines should exclusively use the TWS 10/60 (no longer available I think, so Racing Syntec replaces it), but that would seem justified for hard driving in hot weather. The M engines are high performance power plants generating lots of heat - consider that platinum plugs are not to be used on our cars. BTW I use Split Fire plugs, definitely recommendable. But for normal driving under no extreme temperatures like we have now, a 5/40 or 10/40 synthetic oil would be fine.
I use full synthetic Magnatec for its attraction technology, as cold starts are where the engine gets most wear.
Yes I used this oil in my E30 M3 on the recommendation of my dealer and I use the newer version , GTX 10/40, in the M5 and there is a noticable difference in the cold start in the morning.

When I changed in the M3 it was night and day, but as I live in the south we do not get the extremes of weather that you do in Scotland.

Hope this helps.

In previous cars I have used Mobil 1 but this I think is too thin for our engines.

For a track day I may up the spec but so far I am happy with the performance in regular driving in non extreme environments.
 

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Discussion Starter #13
What do you recon, had the car in the garage today for another job and the've now advised that I have a slight oil leak ??????
 

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A couple of years ago. Mobil1 people bought a brand new 325i and drove it regularly for 500,000kms. They would change the oil every 5,000kms with Mobil1 (15w50). They then opened the engine and sent the parts to BMW. BMW has an internal quality control system for engine parts. For off the assembly line cars, quality of engine parts have to have a rating of 1-2, out of 3-4 (being unacceptable).

When BMW technicians inspected the parts, they gave it a rating of 1. Mind you, this is not a thin oil such as 5w60 or 0w40...

I don´t know about you guys, but this is pretty convincing stuff...

Furthermore, one of my mechanics is a German ex-race car driver who also worked for BMW in the homologations department. He owns an e34 M5 and will only use Mobil1 (15w-50)...

The e34 M5 does not like very thin oils. If the oil is too thin, it´ll start leaking.

Regardless of your preference for oil, the fact is that synthetic oils ARE better oils. Look at this picture, I´ve kept it for some time, it belongs to a chap (I don´t remember who, my apologies) whose M5 had approximately 200,000kms. He would change the oil every 5,000kms always with synthetic.

Look at it!!! Any questions?
 

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