Oil Analysis Saga

[Hardazclay]

Since owning my GX I've always changed the oil every 5,000 miles with Amsoil Signature Series 5w-30 and an OEM filter. Amsoil claims you can go 20,000 miles before replacing the oil and filter (with their filter that is). I figured since this oil isn't cheap it would be interesting to see what oil analysis say as I conservatively extend my oil change intervals.

I've been using Speed Diagnostix and I'm happy with the format and information of the reports. You'll see the report shows 2 tests for comparison. I'm happy to see wear metals per 1,000 miles has actually decreased with the longer oil change. I plan to take another sample after 7,000 miles per the recommendation. Hope y’all enjoy the data and my experiment.

 

[folivier]

If you go this route it's a good idea to continue replacing oil filter at a regular interval between oil changes.

 

[Hardazclay]

If you go this route it's a good idea to continue replacing oil filter at a regular interval between oil changes.

I've never changed the filter before without draining the oil first but I would imagine I would lose close to a quart. Enough that I would have to top it off with fresh oil. The new oil is going to add another variable to my experiment and throw off the data.

I totally see your point but if I'm going to get under the car I'm just going to do a full oil and filter change. I think I will open up the filter next time just to see what I find and determine if the filter is going to be my limiting factor.

Regardless I don't see myself going to 20,000 miles like Amsoil claims. If I can get to 10,000 miles and keep wear metals were they currently are then I will be pretty happy.

 

[efjayatee]

Why would longer oil changes decrease metal wear??

 

[Hardazclay]

Why would longer oil changes decrease metal wear??

I'm not saying that is necessarily true. The oil analysis shows wear metals per 1,000 miles driven on that oil change. My longer oil change had lower wear metal numbers per 1,000 miles. So it showed a decrease in the average not necessarily a decrease overall.

A majority of my miles on the longer oil change were highway miles. We took a nearly 3,000 mile road trip and lots of longer highway drives. I believe all those easy miles in a short period contributed to the lower wear metal numbers. The analysis also showed the oil still had life left and was still doing it's job.

 

[bj70bc]

There are reasons to change the oil other than wear metals and oil life, past 7500mi, 10k mi is very debatable even.
These two data points arent the whole story for engine longevity

 

[Hardazclay]

There are reasons to change the oil other than wear metals and oil life, past 7500mi, 10k mi is very debatable even.
These two data points arent the whole story for engine longevity

Please feel free to share your data points. I started this thread to hear people's thoughts and share the truth data of my oil analysis. If you haven't thoroughly read the analysis I would encourage it because there are many details like viscosity and fuel dilution that are still within spec.

 

[bj70bc]

I should have said considerations rather than data points perhaps


important stuff is at 12:30 -13:45 min or so
something to think about other than just a print out

 

[efjayatee]

Cool data.

I just change oil every 5k or 4 months with all of my "adventure" rigs. All synthetic

 

[Rednexus]

I change all of our cars at 5k. My tractor - which gets 50-60 hours of use a year - also gets changed annually. Mobil 1 is cheap at Wal Mart and genuine Toyota filters are cheap enough at my dealer that there isn't much ROI on running an oil analysis to justify longer OCIs.

I also came over from the Subie world where even 6K OCIs will give you an oil burner with gummed up rings

 

[Gxunit201]

Since owning my GX I've always changed the oil every 5,000 miles with Amsoil Signature Series 5w-30 and an OEM filter. Amsoil claims you can go 20,000 miles before replacing the oil and filter (with their filter that is). I figured since this oil isn't cheap it would be interesting to see what oil analysis say as I conservatively extend my oil change intervals.

I've been using Speed Diagnostix and I'm happy with the format and information of the reports. You'll see the report shows 2 tests for comparison. I'm happy to see wear metals per 1,000 miles has actually decreased with the longer oil change. I plan to take another sample after 7,000 miles per the recommendation. Hope y’all enjoy the data and my experiment.

I appreciate your experiment. I will be following along.

 

[Hardazclay]

I change all of our cars at 5k. My tractor - which gets 50-60 hours of use a year - also gets changed annually. Mobil 1 is cheap at Wal Mart and genuine Toyota filters are cheap enough at my dealer that there isn't much ROI on running an oil analysis to justify longer OCIs.

I also came over from the Subie world where even 6K OCIs will give you an oil burner with gummed up rings

I'm definitely not getting a ROI for these oil analysis reports thats for sure. If I was smart with my money I would go back to getting my oil and Toyota filter at Wal-Mart but luckily for Amsoil I'm not and throw lots of unnecessary money at a 19 year old SUV.