Latest oil test results

interestingly, in the synopsis, they don't talk about longevity.

6.3) page 42 states that most manufacturers recommend 7,500 miles for either dino or syn.

 

Wow, what a gutless paper.

All those pages summed up in section 7. Synthetic may be better than conventional. If you pay the added cost for synthetic it may be better for the engine. If you drive the severe schedule, you should consider synthetic. And of course follow owners manual.

That's like an investment firm saying children from families with 529 college funds tend to graduate college. Ya think?

 

When Synthetic first came on the market, I saw lab analysis tests (truck engines) which indicated that synthetic, with filter changes, was often lasting 2-3 times as long as conventional oils. Today, many car manufacturers have embraced synthetic, but most aren't taking any advantage in this - that's if those early test results were correct.

The WIKI article on synthetic oils gives a number of advantages which includes:

• Extended drain intervals, with the environmental benefit of less used oil waste generated.

The argument I last heard was that they prefer to have vehicles coming in for service regularly as people are tending not to check tyre pressures or tread, radiator fluids and oil levels like we did 40 yrs ago. Yes, good point. My question back was - why not just change the filter, check all the fluids etc without wasting oil if it's not necessary. Shoulders shrugged.

 

good question. and now, everyone in the 2010 oil burning threads are recommending 5k oil change.

 

With some of my "cheap" cars - for the kids at Uni etc, I would put good oil in, but change the filter regularly, only changing the oil at every 2nd service. They ran fine, with no ill-effects. An acquaintance who ran a delivery firm with a few vans and light trucks would send his oil for analysis pre-service, and he was changing his oil only every 3rd or 4th filter change - but his vehicles were running all day, not warming up and cooling down like most of our cars which would be better for the oil.

 

it's almost as if we can't trust these oil tests, but maybe there's something else at play, and we're on a false trail.

 

Wife's beater car is a 02 Infiniti G20 with close to 200k miles. The paint and the interior plastics are deterating. We are waiting for it to fail the state test and neglected most of the maintaneses since a few years back . Oil changes whenever Firestone offers the discount - generally 7k to 10+k per change with cheapest oil offered. Recently just passed the California biannual smog check with flying color. Still gets 30+mpg. It is going to stay for another two years.

 

Honda advocates the opposite: oil filter change only at every second oil change. AFAIK, they don't publish official schedules, instead rely on built-in Maintenance Minder, which counts down percent, and from 15% downward shows a code, for example:

A1, which is oil change and tire rotation

and:

B1, which is is oil-and-filter change, and tire rotation

In my experience the it was always one, then the other.

 

Yes, I think some manufacturers do that, though most do both at the same time.

I was thinking more of fleet situations, where servicing is a major expense, not just from the cost, but also having a vehicle off the road and unable to use it for work. The oil analysis he used advocated changing filters even if the oil wasn't changed. The other thing which the oil analysis would do is identify wear trouble-spots in engines by identifying metallic and other compounds in the oil, besides the normal things like oil condition, viscosity etc.

I couldn't find a local one, but Googling found a USA report which sort of says the same thing:

When Should You Change Oil? - Articles - Maintenance - Articles - Government Fleet

 

Wow, that looks like a Deadly serious issue!

I used to scratch a mark on the oil filter canister. It was easy to see if they changed it then.

 

That will not work on the Prius. the canister is not replaced, only the element inside it.

 

That's one downside to the permanent oil filter housing. One owner here discovered NO oil filter when he got into his first DIY oil and filter change, basically had run the car without filter for the duration of the US interval: 12 months or 10K miles. Doing my own oil changes, a couple of times I've just caught myself, about to put the cap back on sans new filter. The problem: it's possible.

 

When was the last time you or anybody you knew had actual engine issues due to poor oil quality or not changing it? How many actual failures?

When synthetic oils first came to the US they were true Type(or is it Group) IV synthetic oils. The Castrol came out with Syntec, calling it synthetic, but was actually a mix of Type IV and Type III, which are highly refined conventional oils. Mobil took them to court for false advertising but lost. So nearly everyone changed their synthetic oil formulas to what is actually a synthetic and conventional blend. If you are buying a synthetic oil, get a 0w-xx weight; they'll have a higher percentage of Type IV oils.

On a somewhat related note, the switch to ultra low sulfur gasoline will extend the oil life in US cars. We should see change intervals close to that of what European cars have with it. If the dealers don't interfere.

I always found that odd. By the time the oil is black, the filter is likely clogged and its bypass valve open. I once changed the filter without changing the oil. After week, the black oil did not go back to out of the bottle new, but the color was brown and transparent; maybe a little cloudy.

Oil does not need to be changed because it stops lubricating. It needs to be changed because protective additives get used up. These fall into two groups; anti-seize and acid neutralizers. The anti-seize ones get used when the inevitable metal to metal contact occurs, mostly during start up. GM's oil life monitor is based upon the known consumption rate under different conditions for a commonly use anti-seize compound.

The acid neutralizers get consumed because the tiny specks that make the oil turn black become acids when water eventually gets into the oil. I figure taking the old filter out should extend the life of these acid neutralizers by taking the gunk it has caught out of the oil.

Oil analysis is a great tool for fleets. Big ones might even have their own lab. For those driving over the typical annual miles, it can help save owners from unneeded oil changes once they determine how long the oil will last for their situation. I've never tried it because it costs the same or more than doing the oil change myself.

 

16 posts, and i still don't know when to change my oil, or what oil to use.

 

If you don't know after 56K+ posts and 12 years, you truly are hopeless.

 

Easy: I just slam in fresh oil/filter every six months. Toyota Canada told me to, lol. Kilometers never enters the picture, with our lifestyle, lucky to do 8000 kms yearly.

 

yep, i just follow mfg.'s recommendations. after 12 years of reading oil threads, i haven't seen any compelling evidence to the contrary.