"Flex Fuel" Tundras and 5,000 mile OEM oil change interval?

[sixdogs]

Toyota says 5,000 so do it at 5,000. Oil is cheap, engines are not.

Agreed. But, why is my oil change interval on a FFV that burns regular old normal pump gas 5,000 miles while the exact same vehicle that is not a FFV and burns the exact same pump gas has a 7,500 or 10,000 mile oil change interval? That is what I do not understand.

 

[Patches]

Agreed. But, why is my oil change interval on a FFV that burns regular old normal pump gas 5,000 miles while the exact same vehicle that is not a FFV and burns the exact same pump gas has a 7,500 or 10,000 mile oil change interval? That is what I do not understand.

sixdogs; I may have led you astray by saying my '07 oil change interval was 7500 miles; by the manual, the change interval on that vehicle was 5000 but I chose to go to 7500 because of the use of synthetic oil. The manual stipulation of 5000 miles was with the use of conventional petroleum oil, as of that period Toyota did not recommend the use of synthetics, for some strange reason. The recommended interval on my '16 is 10,000 miles, but the engine is identical to the '07 Tundra; a decision you'll have to make for yourself

 

[3930dave]

Classic science experiment... are you totally sure you only modified one variable ?

"Identical" engines ? Is it likely that a major manufacturer modified absolutely nothing in a high volume engine design over a decade ? Possible - yes, Probable - no.

Even if the engines are exactly identical over time, I can understand that a conservative company like Toyoda would want to see a great deal of real-world data before extending something as critical as oil change interval - could be just one new hydraulic actuator/control in the start of an engine production run that they want to extensively validate before authorizing OCI extension...... Just one example, but you get the idea....

From another direction...... oil specs (even conventional) have changed a great deal in 10 years. This alone can explain longer durations, IMO.

Some refinery guys hang out here now and then.... they might know the timelines..... diesel gets most of the attention, but I believe sulphur has been knocked down over time in gasoline too. Gasoline formulation, in general, definitely changes over time.

I don't consider myself an expert on most of this stuff. What I do know is that being able to 100% guarantee that you've only changed one variable in a complex system (esp. over a long period of time) is more of a challenge than it first appears.

Rgds, D.

 

[sixdogs]

No one's totally assured of anything, every. But, for this experiment it's a simple question that needs an answer without a lot of exclusions. These engines are similar enough that there is likely some obvious answer that's being missed. It's either that or Toyota has dropped the ball on oil. There is precedent for this since Kubota only recently allowed the use of 15W40 oil in their engines in the last few years despite the widespread use of it. Same with synthetic oil that only recently got an OK to use after previously being prohibited.

So it's either something or nothing. There is either a major reason or much ado about nothing. I would like to extend my synthetic (required) oil change interval beyond the required 5,000 mile limit but don't want to miss some obvious issue. A 5,000 OCI wastes time, energy, money and natural resources. It's OK if need be but not OK if not need be.

 

[Patches]

I can only attest to my personal experience in this; that being, I owned an '07, 5.7 Tundra for a period of 9+ years and used a 7500 mile OCI with Mobil 1, 0W30 with no ill effects. This was no garage queen, towed often during the summer months, often up to 13,000 pounds, which is the reason I used 0W30.

 

[sixdogs]

I can only attest to my personal experience in this; that being, I owned an '07, 5.7 Tundra for a period of 9+ years and used a 7500 mile OCI with Mobil 1, 0W30 with no ill effects. This was no garage queen, towed often during the summer months, often up to 13,000 pounds, which is the reason I used 0W30.

I've towed 12,000 a couple times and since it's only rated 9800 was a little concerned. I rarely do it. Then a friend of mine told me that a number of his friends routinely tow 13,000 =/- and have done it for years with no ill effects over lots of miles and hilly ground. I use 5W30 in the towing months.

 

[3930dave]

No one's totally assured of anything, every. But, for this experiment it's a simple question that needs an answer without a lot of exclusions. These engines are similar enough that there is likely some obvious answer that's being missed. It's either that or Toyota has dropped the ball on oil. There is precedent for this since Kubota only recently allowed the use of 15W40 oil in their engines in the last few years despite the widespread use of it. Same with synthetic oil that only recently got an OK to use after previously being prohibited.

So it's either something or nothing. There is either a major reason or much ado about nothing. I would like to extend my synthetic (required) oil change interval beyond the required 5,000 mile limit but don't want to miss some obvious issue. A 5,000 OCI wastes time, energy, money and natural resources. It's OK if need be but not OK if not need be.

Sx class oil specs evolving is probably the one major factor. If you are looking for one significant smoking gun (engines blowing up), you aren't going to find it. Toyota specs their products conservatively, and as I and others have attempted to illustrate, they have to issue Maintenance requirements for all customers, under all conditions.

If you want to save money on oil changes, then by all means, go ahead.

Rgds, D.

 

[Spindifferent]

The OEM on these Tundras mandates a 5,000 mile oil change with a flex fuel engine. Period. End of discussion. By the way, I run Mobil1 5W30 and tow 1/4 of the time.

Come on, this doesn't make sense. I know the oil has lots of life in it so what's so special about a flex fuel vehicle that means change the oil at 5,000 miles in a 7,500 or 10,000 world? Do we go to He** for failure to comply? Find our beds short sheeted at night? Maybe the engine takes a powder and throws a rod through the pan?

**Come to think of it, my 2015 Tacoma 4 cylinder regular fuel engine also mandates 5,000 mile oil change. Surely, I'm the only one out of the loop here and I don't get it.

It is the design of the engine that determines the OCI (oil change interval). I have a 2013 Tacoma SR5 with the v6 engine. Toyota says that the OCI is 5000 miles for this engine whether you use synthetic or non-synthetic oil. After the free non-synthetic Toyota oil changes were done, I switched to Mobil 1 and am now on a 7500 mile OCI because synthetic oil has greater wear durability. The 3rd gen Tacoma (2016+) now has a 10,000 OCI as it has a new and different engine than the previous years.

Oil and OCI is like talking religion and politics to strangers; to each their own is my moto. :confused2:

 

[WilliamBos]

Re: "Flex Fuel" Tundras and 5,000 mile OEM oil change interval?

Have you ever pulled a valve cover to see if you have a sludge build up from longer OCI? Bets Toyota set 5,000 for a reason, could be timing chain related, could be a guide issue.

I would not over extend the OCI unless you know for certain no harm will come of it.

 

[houstonscott]

Have you ever pulled a valve cover to see if you have a sludge build up from longer OCI? Bets Toyota set 5,000 for a reason, could be timing chain related, could be a guide issue. I would not over extend the OCI unless you know for certain no harm will come of it.

I had a 1999 suburban with the 5.7. Used mobile1 and after 135k a cam had a flaw and the engine was replaced. I was surprised how much sludge was in that engine. Everywhere oil pooled was black sludge.