Synthetic oil change interval?

[Ross]

According to 632regals poll roughly 70% of us use synthetic oil.
I'm interested in the change intervals you all are using.
I've just made the switch to Mobil1 10/30. Engine is currently dry, I'll be watching for leaks and if they sprout like the last time I used the stuff it's back to dino.
Meanwhile, how long do you guys run it?

[632 Regal]

i go ~5k between. I also use the thicker 0w-40... scour the local stores til I get like 9-10 qts for the next interval (the V8 takes 8 qts)

[Ross]

Thanks. Scour the stores is right, I wanted 10/40 but settled for 10/30.

[Russell]

about 5,000 miles. I currently use Castrol Syntec 5w40.

[zman-95-540i]

I also do around 5k miles. Usually Mobil1 15w50 but I am about to put some Redline in that I found on sale.

[swenpro]

i go ~5k between. I also use the thicker 0w-40... scour the local stores til I get like 9-10 qts for the next interval (the V8 takes 8 qts)

0w-40 is thicker than...... ? I was under the impression that zero weight meant a thinner oil.

[BMWCCA1]

Low number is what it can break down to eventually, not necessarily what it runs at even cold start temps. I believe Mobil took the 15-50 and stuck a new high-mileage label on it so they could charge a buck or so more for it recently. That's what I was using. Guess now I'll have to go with 5-40 which is what the previous owner used in my current car.

[Bill R.]

mobil 10w30. 0w40 is thicker than 10w30 at the temperatures that you use it at. This has been explained many times before. A 0w40 is a 0 weight at cold temperatures for quick oil flow to the bearings when first started. But it is a 40 weight when it reaches the normal operating temperatures for the engine oil temp which is close to 100C or 212F. The 10w30 is slightly thinner at operating temps and pours a little slower at low temps than the 0w40 does.




0w-40 is thicker than...... ? I was under the impression that zero weight meant a thinner oil.

[califblue]

5K here, I use Royal Purple 20/50;)

[bigtisas]

I noticed many people check oil at 5000 interval. I thought synthetic oil can last a lot longer like 10000 miles.

[Russell]

Wrong! Google for some of the oil forums and you will see that many people do go 10,000 miles or more. They generally do so after careful oil analysis to see how the oil's additive package is holding up. Again, many of us just over maintan our vehicles. :)

[mikell]

4500 to 5000 miles

[Fetch]

i go ~5k between. I also use the thicker 0w-40... scour the local stores til I get like 9-10 qts for the next interval (the V8 takes 8 qts)

Sorry, don't mean to hijack, but...
Jeff, I'm still trying to understand lifters,
I'm in the midwest btw,
Thinner or thicker oil is better for lifter functioning (especially mine w/150k on them)?

do you understand what I'm asking lol?

Is the 0w40 a good choice for the M60 & its lifters, etc?
Would the 0w40 be good year round because of it's thin cold weight?

end hijack :)

[632 Regal]

my engine seems to like the 0w-40 and I have a couple miles on it too. The thinner helps at startup, it fills the lifters faster and at temp its thicker so that it protects and has less leakdown than say a 30wt oil

hope that helps some

edit: yes it's a great choice year round.



Is the 0w40 a good choice for the M60 & its lifters, etc?
Would the 0w40 be good year round because of it's thin cold weight?

[Boone.Msi]

i changed from synthetic castrol 10w40 to synthetic mobil1 0w40 and my car runs twice as good as it did before i did the oil change. seems like better throttle response, tighter shiftpoints, etc. although it could just be from changing the dirty air filter.

seems like it starts smoother in the cold also. Im stayin with 0w40 from now on.

[rob101]

I use 5W-50 mobil 1, the interval i change is around 7000-7500 km or 4400-4700 miles.

[Ross]

Thanks guys, looks like 5k then. I'll need to resist the urge to change it sooner.
Perhaps someone here could tell me how to program the radio to fail in 5k so GF will know the car needs service.

[Russell]

IMO, 0 to 5 as the lower weight seems to be key for cold starts. I found that when I went from Mobil 1 15w50 to Mobil 1 0w40 the cold start clatter was gone. However, my engine seemed louder. No cold start rattle/clatter with Castrol 5w40, yet the engine is quieter. Go figure.

[SnakeyesTx]

According to Mobil1's info, you can go up to 10k intervals, Royal Purple claims 15k.

Usually I do about 6500 on mobil1, and 10k on Royal Purple. Also, I use lucas oil stabilizer as a replacement for 1 quart.

[RobPatt]

e.g. my next will be due soon at 145,000 miles.... then 150,000 miles, etc.

cheers.

[John B.]

I change it every 5K which for me is about once a year. Currently using Mobil1 0/40 but will be going to 5-40 Rotella synth at the next change.

[632 Regal]

if you wait that long you will "feel" an improvement with the new oil, this is cause all the carbon builds up in the oil and causes friction. witout them toilet paper filters the deisels use I wouldnt want to extend mine over 5k miles.

look up Winfreds posts about this and wham, night and day difference in deisels oils, clean as new at 15k miles.

edit: Who the **** is Winfred?


According to Mobil1's info, you can go up to 10k intervals, Royal Purple claims 15k.

Usually I do about 6500 on mobil1, and 10k on Royal Purple. Also, I use lucas oil stabilizer as a replacement for 1 quart.

[BillionPa]

the V8s have a large oil capacity, and if you do mostly highway driving, should be good for 15-20K miles with synthetic.

HOWEVER... if you have lots of short trips, or have high humidity (florida!), or high fluctuations in temperature (minnesota!) then change at shorter intervals.

DO change the filter halfway through if you do a 7-10K interval, and do 3-4 changes with a 15-20K interval. after changing the filter top off the oil to just a bit over the medium point on the dipstick.

M60 hyrdaulic lifters seem to be more friendly to something in the middle of the 40-50wt when hot variety. so i take 0W40wt oil and add an additive with a very high viscosity index, that makes it around a 5W45 (if there was such a thing) and also increases the amount of friction modifiers in the oil, making it more slippery. the thicker oil keeps the lifters more full during valve opening, which = more air in the cylinder.

a 0W30 oil when cold is still thicker than a 10W60 when hot, so dont let the numbers trick you. 0W oil is actually MUCH thicker than 60wt is when hot.

i believe the optimal BMW oil (with hydraulic lifters) would have when hot viscocities equal to specialty formulations SX-up, which is a 44wt oil on my sliding scale, and a K40 viscosity the same as Redline 10W30, but have 0W flow characteristics. Lubro Moly 0W40HD oil comes VERY close to this, and 8 quarts will be going into my car by the end of the week.

[BillionPa]

oh, i was also reading earlier that M1 is probably not full synthetic anymore, but a mix of hydrocracked hydroisomerized dino oil and PAO. at least for the 5W30 variety, probably not on the 0W40.

[Fetch]

interesting thread :)

[Zeuk in Oz]

According to 632regals poll roughly 70% of us use synthetic oil.
I'm interested in the change intervals you all are using.
I've just made the switch to Mobil1 10/30. Engine is currently dry, I'll be watching for leaks and if they sprout like the last time I used the stuff it's back to dino.
Meanwhile, how long do you guys run it?
Mobil 0W-40 and change every 7,500 km.

[Paul in NZ]

i run castrol synthetic and run it for the service interval which is about 12000 km or 7000 or so miles

[rob101]

Mobil 0W-40 and change every 7,500 km.
Fuchs SuperSyn 5W-40 20L for $167.50 are you interested? its BMW LL98 approved.
Fuchs is trying to move into the australian market. I am thinking of getting some of this. hehe I just got a Fuchs price list for our workshop, do you want a geezer? they've got some good stuff here!

[inkstom]

I bought my '94 530i about 2 months ago, and I haven't changed the oil yet. The water pump went out yesterday, so I might as well change the oil and the front brakes too. This is a very helpful thread for me, but I still am having trouble determining what to use when I change the oil.

I live in Texas, more specifically Austin. Its pretty humid here and it gets pretty warm in the summer. Winters we're lucky if it freezes, and its almost impossible to have it get in the single digits Fahrenheit.

I don't race, I do go 130 on the highway sometimes, most of the time I am stuck in city traffic. Does anyone have any definitive answer to the oil the weight of oil I should use? I am more fond of castrol, but I am open minded. To be honest Mobil1 is .30$ cheaper than Castrol.

-Thanks

[Jon K]

Change it at 3 - 4k... its oil, its a consumable. Dont buy that 15,000 miles BS

[BigKriss]

same, mobil 1 5w-50 change at 8,000 kms.


I use 5W-50 mobil 1, the interval i change is around 7000-7500 km or 4400-4700 miles.

[BillionPa]

inkstom. for texas you have operating conditions that will be discussed at the end of this post.

DO use an oil that is spec'd for API SJ (and/or SL), and ACEA A3/B3

DO NOT use an oil that is spec'd for ACEA A1/B1 or A5/B5. these limit high shear rates to levels below XW40HD (3.5 vs 3.7)

if you get oil that is JASO-MA spec'd, add some ultra low friction oil additive, like Valvoline SynPower oil treatment, LubroMoly Ceratec, or LubroMoly molybdenum disulfide. the JASO spec limits friction modifiers for motorcycle wet clutches.

now since you are in texas, the temperature doesnt need a low W grade oil, but you still want an oil with a K40 viscosity between the 90-100 range, and an API grade of 40-60.

if you use a group 5 oil like Silkolene or redline, the high humidity suggests an oil change interval of 5000 miles or below.

group 4 oils like Lubro Moly or Amsoil will be able to go twice that range if the filter is changed, as they have high calcium content and good wear additives.

M1 i would go for 5000 as the anti wear package is weaker to conform to API SM specs.

good oils to get are Lubro Moly Vollsynthase 10W60, Castrol TWS 10W60, and Amsoil AME/AMO 15/10W40 with anti friction additives.

[rob101]

same, mobil 1 5w-50 change at 8,000 kms.
I am thinking about switching though mobil one is like $60 for 5 litres or 70 for 40 weight. that Fuchs one Supersynth, is around $40/L if you buy 20L which should last me about..... 1 year by my calcs. what annoys me is that all the premium grade Fuchs **** isn't sold anywhere off the shelf. maybe i should have been born a bogan because i am sorry but i just can't bring myself to use oil technology from the 1980s in my car (ie dino oil)

[Zeuk in Oz]

Fuchs SuperSyn 5W-40 20L for $167.50 are you interested? its BMW LL98 approved.
Fuchs is trying to move into the australian market. I am thinking of getting some of this. hehe I just got a Fuchs price list for our workshop, do you want a geezer? they've got some good stuff here!
Interesting, Rob.

However I have now trained my local parts shop to stock Mobil 1 0W-40 so it is really easy to just go and buy it, no fuss or trouble.

[Russell]

Wow, I only understand part of what you said. Are you a oil engineer or similar? Even so, I think I am ok her in "change hourly weather" KY with Castrol Syntec 5w40 changes very 4-5,000 miles

[BlueM60]

I go 4-5k before a change. I run Mobil 1 15w50 year round with no probs. I do the least stop/ go driving I can and alot of highway. I usually just like to change the oil when its getting to look a dark brown, I would never go 10k on an oil change no matter what the oil/ driving. I work at a dealership and I see evryday what 15k oil change intervals do to perfectly good engines, 90% of people drive in alot fo stop and go city driving/ short trips etc. This gets moisture, fuel and carbon in the oil and dirties it much faster. Even if I have a short drive where i have to go I will find a slightly longer way to go so then engine at least stays up to operating temp for about 10 mins.

-Ben

[bsell]

I go 4-5k before a change. I run Mobil 1 15w50 year round with no probs. I do the least stop/ go driving I can and alot of highway. I usually just like to change the oil when its getting to look a dark brown, I would never go 10k on an oil change no matter what the oil/ driving. I work at a dealership and I see evryday what 15k oil change intervals do to perfectly good engines, 90% of people drive in alot fo stop and go city driving/ short trips etc. This gets moisture, fuel and carbon in the oil and dirties it much faster. Even if I have a short drive where i have to go I will find a slightly longer way to go so then engine at least stays up to operating temp for about 10 mins.

-Ben
Are you saying the manufacturer is spec'ing 15K between changes? Or is this part of the 'free' maintainence package sold with the car?

Back in the early '90's, Audi sold cars with 'free' oil changes every 7.5k miles. The oil was quite darker than I was used to seeing but I figure they knew what they were doing...:(

The Air Force specs changing oil in their vehicles at least once per year. They do our deisels (supercharged with turbo for top end power!) twice a year I believe.

My gut feeling is we change our oil way too often on the 3-5k per change plan. Short of spending the money on analysis to find out for sure, I figure changing oil at the change from hot to cold seasons or twice a year. We've been doing this with my wife's car for the past 8 years without problem. YMMV.

Brian

[bigtisas]

90% of people drive in alot fo stop and go city driving/ short trips etc. This gets moisture, fuel and carbon in the oil and dirties it much faster.

-Ben

How stop and go driving causes the engine oil gets dirt faster? I heard this for a long time but I still don't understand the logic.