Oil changes - how often

[Skylarking]

Don’t dare put those rego numbers on here!

Nah, I’d put ‘em on and see if any member has bought one of those… then we can hear whether they‘ve had any issues

 

[Skylarking]

I just changed the oil in my SSVR Ute after 9 months and 155km's. Oil looked practically brand new but I'm thinking is an oil change really necessary at 9 month intervals when the car isn't driven much? An oil analysis in these circumstances would likely confirm if the oil change intervals could be extended. I'll start my Ute up 2 or 3 times a week and move it between sheds and take it for a spin around the block sometimes, with a few cold start and condensation factors at play that I'm not sure how relevant that is to oil deterioration.

My SV6 Ute did 3300km's in 9 months and the oil was starting to discolour a bit and worthy of changing I thought.

I‘d expect it’s the condensation from moving cold cars between sheds that can be the problem in your use case… the oil never really gets hot enough to boil out any water or fuel condensate.

An analysis may be interesting to see whether the oil can stay longer but as I’ve mentioned, it’s probably not economical to do at a cost of $30 - $50 when oil on discount isn’t much more. And the “therapy” of an oil change can’t be dismissed

Having said that, I still think modern oils have some extra headroom as compared to the stuff I felt with when first starting to work on my cars… The following testing method may be of interest to some:

Seems like modern oils are rather better properties these days, especially the more expensive stuff, so @ 2000kms, we may be throwing away good oil when it’s unnecessary to do so… But I don’t really know… .

An interesting side thought, as my concerns are cold running, I wonder whether those engine block heaters used in freezing climates could help to get our cars warm before the first engine start. Such may allow them to get up-to temp much quicker, especially in aussie winters. Thus we avoid those cold start wear issues and oil dilution issues while more quickly boiling the condensate out of the oil on not as long drives

PS: Seems a block heater can cause a P0116 “Engine Coolant Temperature Range Mismatch” error since a warm block & cold air intake confuses the system at startup. So GM uses a block heaters (p/n 12367827) with thermostatically controlled cable (p/n ?) that only turns on below 0F (-18C) presumably because it’s below a threshold where such a DTC can be flagged. Kinda makes it useless down under … Fcuken modern cars, can’t even chuck on a block heater with out dramas

 

[Skylarking]

And since oil tests have been mentioned, the following may be interesting to some…

 

[RevNev]

I‘d expect it’s the condensation from moving cold cars between sheds that can be the problem in your use case… the oil never really gets hot enough to boil out any water or fuel condensate.

I've got an F82 M4 BMW (F series was produced from 2014 to 2020) and the temp gauge on the dash measures oil temp not typically coolant temp as we're accustom in most cars. On a stationary warm up, it takes about half an hour (30 minutes running) for the oil temp to reach 100 degrees. Normal BMW operating oil temp is 95 to 105 degrees controlled with an oil thermostat and large oil cooler ducted from the bumper/splitter.

When the coolant temp gauge on the Commodore reaches operating temp in 10 minutes running and you think the engine is sufficiently warmed up to boil off any oil condensation contaminants, the oil likely isn't warm enough to burn off condensation much at all. Condensation is dramatic with our E85 race engines starting them cold for 5 minutes a couple of times turns the oil milky. First track session on an E85 engine will dump at least half a litre of water in the catch can venting the engine from the rocker covers.

 

[Forg]

Yeah as @RevNev says, a properly warmed-up engine doesn't happen for at least 15 minutes & is often longer ... the better half's commute is (according to Moogle Gaps) averaging about 10-12 minutes each way, 10 intersections and about 6km. It's not great for the car, and I'll do the oil-changes in the hope that the best-nick oil will protect it the most.

 

[Skylarking]

I've got an F82 M4 BMW (F series was produced from 2014 to 2020) and the temp gauge on the dash measures oil temp not typically coolant temp as we're accustom in most cars. On a stationary warm up, it takes about half an hour (30 minutes running) for the oil temp to reach 100 degrees.

IIUC, the recommendation from all manufacturers is to not idle the vehicle to warm it up but to simply drive off using light throttle But it’s not ideal whichever what you do it

And the water temp gauge is computer controlled so doesn’t really show the current temp, it’s a fudge so isn’t really helpful for judging actual coolant temp, seems dumbed down to avoid concerns from owners who don’t understand anything mechanical

In my mind, the solution could have been an engine block heater but as I said, adding an engine block heater, with having to cope with DTC’s, just makes it more difficult than it needs to be and thus more annoying

 

[MrBags]

Curious what the oil look like 12 months and 800 kms old?
Ever done an oil analysis?

If I remember I will get a pic or two, never had an analysis done.
I like the Ostrich approach on this, everything is fine!!

 

[RevNev]

IIUC, the recommendation from all manufacturers is to not idle the vehicle to warm it up but to simply drive off using light throttle But it’s not ideal whichever what you do it

Idling and loading a cold engine isn't good although I don't know if this is theoretical or physically proven, but I tend hold the revs up a bit on an engine warm up at 1500rpm and as it warms up, a few revs to maybe 2500rpm.

I let a VF V8 idle on cold start until the rpm drops enough to select a gear without standing on the brakes too hard to stop the car moving (auto trans) and drive off on light throttle. That's were I'll hear a bit of LS3 piston slap with the windows up and radio off for a minute or two.

I remember telling one of guys warming up our VZ Supercar engine, don't rev it cold, be careful with the wicked throttle response of these engines. Sure enough, a blip on the throttle spun the engine onto the rev limiter (7500rpm) stone cold. "It wouldn't have gone more than 3000rpm" he said until downloading the data told us the engine bounced on the limiter to 7930rpm momentarily!

 

[RevNev]

I still think modern oils have some extra headroom as compared to the stuff I felt with when first starting to work on my cars

In 2007 we had 3 race cars running with identical engines (V6 Ecotec's) one on the old Mobil 1 15w50 full synthetic and the other 2 on Castrol GP50 25w50 mineral oil. We didn't run sump baffles at the time and we discovered oil surge under brakes at Phillip Island. The Mobil 1 engine spun a big end suffered a damaged crank from zero oil pressure, but the GP50 engine's didn't with perfect crankshafts and bearings despite the same oil surge zero pressure situation.

When we got the VZ Supercar in 2011, the previous engine builder who did Gary Rodger's engines for many years, told us NOT to use full synthetic oil as it makes 2hp and cuts the engine life down from 4000 race km's to 1100 before a rebuild is necessary. We use mostly Castrol Edge 25w50 primarily a mineral oil that superseded GP50 in our pushrod race engines since with great success.

Larry Perkins promoted GP50 mineral oil in the day and claimed to use it in his race engines and was a true story. Larry believed that mineral based oils had better engine wear protection than full synthetics under extreme stress. We think a full synthetic oil is best but is it really?

 

[greenacc]

I recently changed the oil on the Crewman after a 1,600km trip. The old oil was the usual black, thin and watery liquid that I get each oil change, I don't remember what brand it was, but it was full syn 5W30.
Why did I do the oil change ? Something to do while bored stupid due to crap weather..
The previous change was just on 3 months and 2,700km ago, so 1,100km was short shopping trips beforehand.
That will convince me that those sort of trips will kill the oil.

5W30 oil is thin to begin with. If you did an oil change with 5w30 then drive around the block, add oil flush and drop the oil it going to look watery on day 1. And it will likely already be dark as well thanks to the flush dissolving crap from the engine. So your conclusions from the look of the oil after just a few thousand km are a bit thin, and watery