Kurtz

iTrader: (1)

Because you're literally pouring money down the drain.

A true high-end synthetic can easily go 1 yr/25k miles safely

Under normal use changing it every 5k is exactly as wasteful and pointless as changing your tires every 5k "just to be safe"

A/C

15000 miles interval is sick

i usually change it at 8-9k miles and i can say that when it comes closer to 8-9k miles the engine starts to run not as smooth as before, roars much than before. Not a healthy sound at all

at 15k miles it should run like a tracktor ))

Kurtz

iTrader: (1)

My last car, which didn't have nearly as clean running a motor as the 2IS, went 25k between changes, made over 500hp, and had no issues with oil cleanliness.

Folks have posted UOAs repeatedly here running 10k and more on conventional oil and the analysis came back the oil still had life in it, so no way synthetic would be anywhere near done before 15k or more.



Keep posting about "how you feel" or "what seems too long" all ya want... the actual science is, heavily, on my side here.

kbkura

Always suspected that the whole "engine oil is spoiled w/in 3k-5k miles" was a scam, but good to have actual proof that it is. I suppose the dealers need continued revenue.

I planned on doing it anyway, but now I feel more comfortable doing an oil change per year (around 10k miles for me). I'll probably use synthetic just to make myself feel better, but all-in-all, I'll still be saving 2x the cost (as Lexus currently recommends an oil change every 6mo/5k mi and I'll be doing it myself).

ecr527

I don't think I'd be comfortable pushing my oil to 15K miles, especially if I were running on conventional oil, but based on some of the test results here, it's definitely do-able. I usually change my oil at around 7500 miles, but it looks like I could easily run it to 10K with no problems.

LexFather

It also depends on driving style. If you drive hard, it will wear down the oil compared to cruising.

Poll closed

Koz

Running quality synthetic 15K mile will not be a problem when 14K on dino has proved to be OK. I'd be concerned about sludge running 14/15K miles on Dino. I'd like to see the valve train. I keep my car too long (min 100K miles) to use dino with extened oil changes.


Koz

Kurtz

iTrader: (1)

Based on the UOAs I've seen I bet your valvetrain would be perfectly fine running dino for 10k...I doubt I'd go much past that though.... (well, I doubt I'd run dino at all beyond the free changes, I'd personally run synthetic and just change 1/yr without much regard to mileage- esp. on a car you plan to keep past 100k).

It'd certainly be fine changing synthetic 1/yr for mileage well into the 20-25k range for a good synthetic.


Again though all this is for normal driving... if you're frequently making very short trips where the motor never gets to operating temp I'd change significantly more often.

Lets Drive

iTrader: (3)

Just to put this comment into perspective, if I recall correctly, didn't you opt to drive your car with a malfunctioning O2 sensor, partly because of cost? The money saved from doing oil changes that frequently would've easily offset the price of an O2 sensor fix. This isn't a cost-cutting issue.

The oil change interval is largely based on an old perception of how often oil should be changed, versus actual analysis proving that extended change intervals are just fine, especially when using oil that is more resistant to breakdown and proper filters. I think a distinction needs to be made between changing your oil for peace of mind, versus changing oil to avoid being 'cheap' on maintenance. Even then, spending on premium oil, or otherwise, and taking the time to send/pay for samples to verify your practices falls into the same category of being cautious, minus the paranoia. Its an objective, safe, and frugal method to care for your car.

A/C

Also I was told that oil change intervals also highly depend on the quality of the fuel you use (amount of sulfur in it too)

for example high quality fuel in Russia is pretty rare, mostly its something acceptable but not perfect, and such fuel gives a lot of wastes into the engine

Koz

The ONLY safe way to run extended oil changes is to first use a quality full synthetic and have the oil analyzed after a reasonable amount of time. Since 10K miles has been proven to still provide safe protection using dino oil. 10K miles would be a good starting point for the first used oil analysis (UOA). Remember a one year time period is a safe cut off for each change. After the first UOA you will get a better idea of how long (Miles) you can continue using that oil (Within one year). Under ideal conditions I would not be surprised if oils such Amsoil 0w-30 could be used for over 20K miles (Within one year).

Using dino oil more than 10K miles could cause sludge build up in the areas of the engine where oil does not circulate well or pools.

Koz

Lancer2.4

$22.50 for 0w30 Mobil 1 Fully Synthetic
$7 for filter media with O-Rings

15 minutes under the wife's car

$32 bucks with tax and a few kisses from the wife.....Super cheap and ready to run for another 10,000 miles easy

IS-SV

Aren't the new RX350's (3rd gen) running synthetic oil with 10K intervals now? (I'm asking, not stating it as fact)

Technique

It can easily go 10k miles with no problems. Look at my other thread which was my first oil change. I went the first 10k miles on the factory oil and blackstone came back and suggested I go 12k the next time and plenty of active additive left. Remember, that was the break-in oil. Subsequent oil changes should be good for longer than the break-in oil.


Why do you say "within one year"? I proved that to be a myth in my other thread where I went THREE years between oil changes and blackstone reported active additive left. Comon Koz!

https://www.clublexus.com/forums/car...-delivery.html

There is no need to change oil just because 12 months has elapsed.

Koz

You are absolutely correct about running longer then one year but everyone’s driving habits are different. If you drive only a couple hundred miles a month, your engine/oil will be exposed to high acid content due to high amounts of condensation mixed with combustion by-products. This could cause corrosion. I tend to do many short trips in the course of a year and keep the engine in the high end of the RPM range. These driving conditions are not considered normal drive habits and need to be considered.

That being said, I’m sure many others may have similar driving habits/conditions and we are talking about a, sort of, “Rule of Thumb” (to be safe).

This is the experts view;

"Our data base has many different engines that have various oil change intervals. We do have a few where the owner has kept the oil in use for up to two years but no longer than that. The percentage of those vehicle owners is quite small but we can tell you that the oils we have tested for them have shown average wear for the vehicle.

Most oils can hold up for two years without any major problems especially if the vehicle is driven. You average enough miles, per month, that I don't think you would have any problems. However, if that makes you feel uncomfortable, you can always change you oil sooner."

Koz