Oil Change Interval decrease as engine ages?

Any suggestions out there on shortening the oil change interval from 8000km/5000mi once the engine reaches a certain age? I've been keeping my oil and filter changed every 8000 km since I bought the truck at 12000 km on the odom, starting with its first change at 16000 km with synthetic oil, and its been consistently changed with synth. every 8000km since. It now has 160,000 km (100,000 miles) on it. This was the newest vehicle I have ever owned, so my habit of changing oil on my previous higher mileage vehicles at 5000km/3000mi max has me concerned now that 8000kms on an "older" engine may be pushing it. Any thoughts/info provided would be appreciated.

BTW my taco uses practically no oil between changes (maybe 1/8" on the dipstick), and the old oil is dark brown but not black.

 

If you have been that diligent in PM, I would not be too concerned about reducing mileage intervals. I just did a Blackstone Labs test on mine (different engine, 3.4 5VZ-FE) to see how things were going after 120k miles, and I have owned the truck only since 100k miles. Results were outstanding in terms of normal wear, and the oil still had good TBN and viscosity after ~5100 miles (Mobile 1 synth).

I suggest you check out the Blackstone Labs site and have a test done so you have some facts to work with, rather than a bunch of heresay from a bunch of random people and different trucks.... It will tell you what is going on in your engine.

 

It is up to you, but this is a modern engine that has tighter tolerances than engines of the 60 and the 70's. I didn't note your age, but if you can remember the 60's , then you have seen the changes in engines since then. If you use the old knowledge and apply it to today's technology, you will find that it will waste both money and your time. Being careful with your engine is not a problem, but the amount of mileage that used to be considered excessive, now just means it is broken in.
I would just keep on doing what you used too, untill you note a problem.These engines are real robust, and can take a lot of miles till they need any excessive care.

 

No reason to do so.
5000 miles is a perfectly acceptable interval for all but the most extreme conditions (cold weather with the potential for condensation and frequent short trips with no opportunity to boil off the moisture).

Toyota used to allow for both 5000 and 7500 mile change intervals. My '03 Tundra had both intervals available.
Model by model, as the "Maintenance Required" light was added, they eliminated the 7500 interval from the manual since the MR light is simply a 5,000 mile counter.
That was the only reason for the elimination of the 7500 mile interval.

 

At 278k I am still running my 2006 8-12k between drains (with Mobil 1 EP 5W30).

 

Only if the oil analysis tells me the oil is beyond service life at 5,000 miles.

After my warranty is up (extended warranty) I'm switching to at least 10,000 mile intervals with a quality synthetic oil and filter.

 

My 70 Dodge Challenger owners manual called for oil change every 4K and oil filter every 8K. They did say "Because of higher clearance necessary for its high performance characteristics, the 426 HEMI engine is expected to use oil at a higher rate than other engines"

My 88 Mitsudodge Ram 50 called for Oil every 5K and filter every 10K.

It was US oil change shops that dreamed up every 3K that the car manufacturers never demanded.

Very few cars are in the junkyard for oil related issues if the oil is changed per the manufacturer. A lot of stress is generated by this concern though?

 

If possible, always change your oil at the same interval for the life of the vehicle. Continue as normal.

 

Thanks 2 everyone you've eased my mind. Been using Castrol Syntec 5w-30 and Toyota filters all the way. Also looked after my air filter (went to K&N and clean/re-oil twice a year) and have done all service interval PM work since I got the truck. Drive 95% highway miles. I want to keep this great machine for a long time yet!

 

You are golden then. I'd allow your K&N to get dirty. Believe it or not, they work better that way. Cleaning and oiling twice a year is excessive.

 

53 years. My first car to play with was a 1971 Maverick. Kept it at 3000mi. between changes back then!

 

You may be right, even though I do alot of gravel road travel it usually isn't very dirty after 6 months. Would save me time and money on the cleaning kits...
I'll look at it after 6 months and give it another 6 if it still looks clean. Thanks for the heads up.

 

Just go with the OEM paper filter.
It filters MUCH better than the K&N and it flows more than enough air for the engine.

K&N admits too much dirt... whether clean or dirty. Do a used oil analysis on a couple of oil changes, then go back to paper and run a couple of samples. The silicon levels in the K&N samples will be high enough for Blackstone to recommend that you check your intake/filtration system.

Seen scored cylinder walls in 50,000 miles (with the factory honing crosshatch still visible).

 

Is there any "lifetime" air filter you would recommend that meets or exceeds OEM filter cleaning efficiency? I hate spending nasty cash at the stealership over and over...

 

Buy your air filters from Toyota of Dallas or Titus-Will Toyota.

Considering they're good for what, 20,000 miles? Even at $20, factory air filters are cheap insurance.

There are no "lifetime" or cleanable air filters that I recommend for an on-street daily driver that I care about durability. There are some that may flow better, but none will meet or exceed OEM cleaning ability, and as stated, the OEM filter flows more than enough for a stock or moderately modified engine.

 

I live in Manitoba Canada so my dealership options don't include Dallas.

 

They won't ship to Canada?

Here's Titus-Will:
http://www.partswebsite.com/1sttoyo...tid=10020&subcatid=20099&section=1&type=parts

$16 for the air filter, $4 for the oil filter.
OEM, best stuff you can buy for your Toyota.

 

Thanks for the link. With shipping and stuff I'd have to check my local prices and see how many I'd have to buy from USA to make it worthwhile.

 

Keep in mind the factory interval for the air cleaner is 30K. Studies have show that filters indeed filter better the more dirt gets in them, and the most recent study shows that the air filter does not hurt mpg even if clogged way more than normal recommended intervals.

Including the original factory filter you get to 120K on 3 more throw aways, I decided on 60K between air filters after reading this.

http://www.fueleconomy.gov/feg/pdfs/Air_Filter_Effects_02_26_2009.pdf

 

So what's all the hype about K&N and AFPro S-Dry filters etc. etc. I've been reading on this site for years? I made what I thought was a reasonably informed decision to get the K&N oiled filter and spent some good money doing so.
I guess it really is buyer beware but I am really trying to take the best care of my wheels I can, and I do as much research as reasonably possible before deciding how to do that. Oh well, live and learn, but deciding how to keep abrasives out of my engines block and oil can have potentially serious and expensive consequences "down the road"....

Thanks again for some insights everyone. And that clogged filter report was pretty cool...