Official 997.2 service intervals too long?

[911Time]

Oil changes were every other year. C2S was over about 7 years and the C4S is just over 9 years ownership now.

Hard to generalise about the use, but mostly shorter trips as a DD, with the cars alternating for the Euro hols 2-2.5k twice a year plus longer U.K. trips from time to time.

That's interesting (thank you), so in the case of your C2S, that's about 3 - 4 oil changes over a 7 year period, which equates to between 12,500 - 16,000 miles per change, based on 50k miles and around 5 changes, or every 10,000 miles for your C4S (also based on 50k). A good oil change regime, that's comfortably less than the 20,000 mile potential frequency.

FWIW, I think any bore scoring/cold pickup issues with the 9A1, will be very limited, largely because the specific combination of causal factors, will be limited to start with but they will (and do already) exist. If the first owner drives the wheels off the car from cold for the first few miles and then gets stuck in traffic, for the next 15 - 30 minutes, their engine will be subject to the worst combination of factors.

Unlike most owners on this forum, who tend to be enthusiasts, those sort of drivers often have little mechanical sympathy, or a rudimentary understanding of vehicle engineering and will believe the car was engineered to withstand any and all sorts of driving without complaint. The concept of taking the time to warm-up the car, would be lost on them and it's unlikely they will see any problems during their ownership.

If you buy a car new, or nearly new, it's far easier to mitigate any potential engine problems but buying one used, that already has maybe 20-30k miles on is a different matter, hence erring on the side of caution regarding oil change frequency because you can't undo what's already been done, but you can prevent it from getting worse.

For my work/lease cars covering 20k per year as required normally once in a three year ownership.

For my 996 covering 5k per year once a year and I'll probably stick to changing the oil myself for my 997.2 every year as well.

As to driving my car does a few short trips in London but more long distance ones to West Country etc so it gets driven reasonably hard.

I saw an ad for a rare Porsche the other day that had covered less than 14K in its 20 plus life but had 26 dealership service stamps, just seems ridiculous amount of work on a car thats done less than the average car does per year.

For a car that you own, changing the oil/filter yourself is so easy and only c£150, IMO it's a no-brainer to do it once per year anyway.

 

[Magic919]

For the C2S I did get to undo the past. They fitted a new engine about a month or so after I bought it.

 

[Alex]

I service mine every year and for the last 2 years have sent my oil off to Millers: http://911uk.com/viewtopic.php?t=140757

Both times the report has come back that the oil is f**ked. That's enough evidence to tell me you need to service it every year.

9000 miles/12 months:

5,300 miles/12 months:

 

[911Time]

For the C2S I did get to undo the past. They fitted a new engine about a month or so after I bought it.

Interesting Magic. What led to the replacement?

I service mine every year and for the last 2 years have sent my oil off to Millers: http://911uk.com/viewtopic.php?t=140757

Both times the report has come back that the oil is f**ked. That's enough evidence to tell me you need to service it every year.

Thanks for that info Alex :thumb:

Says it all really - better to err on the side of caution: it's surprising just how quickly (relatively), even the latest Synthetic oils can shear down to a lower viscosity and fail to provide the sort of protection you might expect at higher temperatures. Plus your example is with a 5W-40 oil, which would tend to have less propensity to shear, than a larger range like 0W-40.

Edit: A further thought, in relation to the OP's question, Viz the 997.2: The fact that your car is a 996 (without DFI) and still shows fuel dilution and oil shear within a relatively small mileage, would suggest that a DFI engine, that is used for primarily for short journeys (failing to reach full operating temp) and thereby failing to fully utilise it's fuel load (through less efficient atomisation), when also driven by an owner who regularly canes it from cold, would tend to suffer far worse fuel dilution issues, than the indirect injection 996 engine, if both are operated in a like-for-like scenario.

Just to be clear, I'm not suggesting for a moment that you cane it from cold, just postulating what might occur if the original owner of a 997.2/991.1, did so and how the difference in injection method, might exacerbate potential issues, for a subsequent owner, down the chain.

 

[tob_today]

I'm old skool. I have annual service every year with MoT regardless of mileage or car. Several decades later and never had any issues with my cars. Sure I probably could have saved some cash along the line, but don't really care. Most likely saved me much bigger bills and headaches.

Personally I think there's a lot of marketing and keeping level with competitors involved with longer service intervals. They are selling to people in earlier years of car life, not to the people picking up down the line.

My 2 cents

 

[Robertb]

@Alex- Those reports are interesting... it would be revealing to compare a sample from a car that had done the same mileage over 2 yrs, and one with higher mileage over two years (or even one year) to see if the viscosity and fuel dilution is a function of time, cold starts or mileage.

My thinking is a car that's used regularly for longer distances is likely to fare better on the basis that cold running is going to be a relatively smaller proportion of total running time.

 

[Alex]

I'll bet if I had a spirited driving weekend the day before I took that oil sample, the dilution would be virtually zero percent. Would be interesting to then see the viscosity of the oil.

 

[MaxA]

For a car that you own, changing the oil/filter yourself is so easy and only c£150, IMO it's a no-brainer to do it once per year anyway.

I've always changed the oil annually and at most I was only ever doing 20k km (12.5k in old money) a year. Nowadays substantially less, but with more track work.

The good thing about a 12 month service and inspection cycle for the ordinary motorist is that a decent garage will look for wear on consumables, and play in suspension, and random oil leaks, and that can only be a good thing for the rest of us.

I discussed lengthening service intervals with a mate in the trade several years ago - a major manufacturer - and he told me that the primary driver for the extended intervals was the demand for reduced opex for the firms doing car leasing and car finance - most new cars can manage the first 3 or 4 years with only oil change/service somewhere in the middle of that time frame and still have a FSH when they come off lease.

 

[911Time]

I discussed lengthening service intervals with a mate in the trade several years ago - a major manufacturer - and he told me that the primary driver for the extended intervals was the demand for reduced opex for the firms doing car leasing and car finance - most new cars can manage the first 3 or 4 years with only oil change/service somewhere in the middle of that time frame and still have a FSH when they come off lease.

That doesn't surprise me. The move towards leasing has had it's downsides - first owners who are literally not 'invested' in the vehicle and are therefore none too bothered about the long term effects of how the car is driven or looked after and the lease companies, whose interests are obviously driven by profit. Any potential problems, for owners down the chain, aren't of any concern to them.

 

[base-1]

I discussed lengthening service intervals with a mate in the trade several years ago - a major manufacturer - and he told me that the primary driver for the extended intervals was the demand for reduced opex for the firms doing car leasing and car finance - most new cars can manage the first 3 or 4 years with only oil change/service somewhere in the middle of that time frame and still have a FSH when they come off lease.

Can absolutely second this. I've also never met a single powertrain engineer that thinks these very extended intervals are a good thing, despite the evolution of oil etc