Maybe it's time to try E85

Also increases your friction along with the ECU dumping more fuel in to keep the catalytic converter lit up to proper temperature. The cylinder walls are a smaller diameter due to being a colder than designed to be at operating temperature.

* When the engine is cold, both the piston and cylinder wall are cold, so there is an equilibrium in design diameters. Any significant wear here comes from lack of lubrication.

* When the engine is warming up, a thermostat or electric water pump is usually closed or operating slowly, allowing the piston and cylinder wall to heat up and expand at as close to the same ratio as possible. This is why being gentle on an engine that is warming up is important. If you warm it up too fast by excessive power requirements, the inside expands much more rapidly than outside the cylinder, causing an expansion ratio imbalance.

* When an operating engine constantly keeps the cylinder walls at a colder than designed temperature, there is a diameter-ratio imbalance outside of design spec. The outside is small and the inside is large; the worst possible combination. At first you'll see increased compression, but over time as the engine wears, you will see a rapid decline in performance and reliability of the motor.

An extreme example of this is an outboard boat motor run in extremely cold water with a sticky thermostat, usually by debris/sand in the water. The engine comes up to speed and runs hard with minimal water flow. Engine gets extremely hot then the thermostat pops wide open, flooding the engine. The cylinder wall rapidly decreases in diameter causing piston lock. This is why on an outboard, servicing the thermostat is so important on outboards.

The engineers who designed the motor know the exact metals, expansion ratios of those metals and set a design operating temperature. Too far outside the designed operating temperature and you're asking for long term trouble. I always cringe when I see someone do a thermostat mod on their trucks and post about it on forums thinking "colder is better".

I have spoken.

 

I am not talking about any engine not lasting as long on 87. I am talking about the specific engines in the Tundra, as per the quoted text in my comment.

Plenty of engines are perfectly fine running on 87 and do not retard engine timing to do so. the Tundra engines however DO retard timing, and retarding timing causes premature wear, regardless of your personal experiences.

 

Proofs? I can disproof this:

Maybe was true back in 1970. In 2022 unburnt fuel will be quickly detected by front H2OS, fuel injectors timing adjusted, no more fuel excess. Power will drop, yes. Add on top of that electronic throttle and VVT on both camshafts - ECU has plenty of knobs to turn. Yes, there will be a knock or two once in a while, because ECU continuously adapts to fuel quality, air temperature, engine health, everything. It will be happening even with 93 octane. Proof is STFT always oscillating in 0.98-1.02 range in order to find the best AFR, with LTFT slowly adjusting to the trend, so STFT won't divert much from 1.

There was a good Bosch Motronic ME4.4 or ME7 writing about how engine management works, for ECU programmers, but I can't find it on the net anymore.

Also stay away from any ECU tune that claims MPG increase, even slightest. Running on lean AFR is bad, as it lets the hot unconsumed oxygen to chew up anything it gets to in exhaust, starting from exhaust valves.

 

Why do you keep talking as if I am claiming that all engines need 93 octane?

I am talking about 3 very specific engines here. Engines that have been tested repeatedly with tangible results that clearly show they should be run on 91 or higher octane for maximum longevity.

It isn't about excess fuel. Retarded timing of the point of ignition during the compression stroke will result in incomplete combustion, regardless of the amount of fuel in the combustion chamber. It isn't a matter of how much or how little fuel is present, it is a matter of the conditions under which the ignition is applied. Retarded spark timing means the cylinder is not at optimal compression levels, which means the temperature inside the cylinder is too low and the fuel and air are not mixed properly. Meaning, some of ANY fuel present, no matter the quantity, will not be burned, because the conditions will not allow it to be burned.

No amount of long term or short term fuel trim will fix that. And the computer will NOT just advance the spark timing to compensate because doing so will only result in detonation, which will wear the engine out faster than incomplete combustion will. So either way, you get premature wear. The ONLY solution, is to run higher octane fuel.

 

There is absolutely no reason to run octane higher than 87 naturally aspirated on stock tune. Ask @Tileguy

 

Except for the reasons I laid out in my previous few comments.

 

I’m sure you know more than the engineers at Toyota.

 

I won’t tell you what fuel is in that bottle.

https://youtube.com/shorts/w3G9VnLBmcg?feature=share

 

I see nearly 40 degrees of timing advance pulling hard with a stock tune on 87 - how much timing are we looking for?

 

I never said the toyota engineers didn't know.

They designed the engine to retard timing on 87 octane. They knew the engine would do that and they knew the consequences of that. They just didn't care. The Toyota engineers don't care if you can get a million miles out of their engines or not. They just need them to last through the warranty period.

That being said, Dustin over at DAP probably does know more than the Toyota engineers. And my information comes from his testing.

 

All manufacturers design engines to retard timing in the event of low quality fuel - that doesn’t mean running premium will get you better efficiency or performance.

Take the word of a guy selling tunes for what you will. I’m sure he is extremely knowledgeable but he obviously has a financial interest in convincing people purchase his product.

I promise one thing - engines with an aftermarket tune have a way higher failure rate than trucks running a stock tune. Those AFR safety margins exist for a reason but lean is mean.

 

This thread is full of people who want to hear themselves talk about a topic they have no experience or education on. Stop quoting myths and politicized articles funded by billion dollar oil companies. Ethanol is better than gasoline in every way possible other than fuel consumption. Nothing stays in your system long enough to attract water and most fuel systems (especially the tundra) are designed to run nothing but ethanol.. I believe ENGINEERED is the word, no?

So much hyperbolic nonsense and personal opinions in these posts. Unreal. Forums can be just as bad as they are good. oof!

 

This is like the need or not need the trans cooler argument.

 

Post your credentials please.

You make a very bold statement about how great ethanol is, when it isn’t; then follow up the statement with more lies.

You complain about hyperbole, yet post nothing but.

Check yourself before you wreck yourself.

 

No. No no no.

Octane rating is NOT a rating of fuel quality and ignition timing is NOT adjusted based on fuel quality.

The octane rating is a measurement of a fuel's resistance to ignition. That's all. It has nothing at all to do with quality.

Read the actual quote. Dustin doesn't say "Buy my tune and then run 91 octane." He says specifically "As we have reported with every truck we have tested on, 4.6L, 4.7L, 5.7L, all run best on 91+ octane whether they are completely stock with stock tune, or tuned."

He is telling people to run 91 or higher octane even if they don't buy his tune. If you don't want to believe him just because he runs a business, fine. But then why do you want to trust the Toyota engineers so much? You think they aren't trying to sell you something?

I have not told anybody to go out and buy a tune or even suggested that anybody should have a tune. I have been saying all along that a Tundra with a STOCK engine should be run on higher octane fuel to maximize longevity. That's all. That is my only claim. And it is verifiably true. You can hook up a scan tool while your engine is running and look at the ignition timing yourself. If it is retarded, you are causing premature wear to your engine. Period. The computer will make minor adjustments of a degree or two here and there, but if you are constantly at 8-15 or more degrees of timing retard, you are shortening the life of your engine. And that's what 87 octane does. Sure, maybe you will still get 300k miles out of it. But your odds are reduced. It's like smoking. Maybe you'll live to 95 years old while smoking 4 packs a day...

 

This is very naive understanding of the problem. Mother nature has such a thing called propagation of the flame front. It is one of the inputs to the successful fuel combustion within the cylinder. You want the flame front propagation to be just about right: not faster, not slower. Now, one of the most important parameters in propagation is the initial pressure. With so many things in the engine affecting the initial cylinder pressure (ambient air pressure and temperature, throttle blade angle, VVT adjusting camshafts, engine speed, etc) ECU actually has to delay ignition, so the fuel starts burning when the mixture is compressed enough for the best front propagation and maximum fuel utilization, so the engine works with best possible efficiency at this load in these conditions.

Denso, Bosch and Siemens have hordes of PhDs working on combustion theory, materials and longevity, yet there's a chip tuning MoFo Corp, who figured out how to adjust ECU's fuel maps and now claim they understand the theory better. Yeah, sure.

 

Ever heard of a knock sensor?

Enjoy your day in the “valley”

 

Some bone stock engines benefit from higher octane and some do not.
After purchasing my 2010 Odyssey I ran it for 5,000 miles on 87, 5,000 on 89 and 5,000 miles on premium. The van saw on average a 2mpg improvement running 89 vs. 87 and 0 improvement from 89 to premium. There was also noticeably less spark knock when not running 87. So, we run 89 in there.
I did the same thing when I purchased my 2015 Tundra. It is also a higher compression engine. I was surprised to find that it made 0 difference. So I run 87 when not towing.
When towing my Tundra yields about 1mpg better with 89.
Spark knock or pre-detonation has many facets and there are may ways to combat it. Every automaker/tuner combats it differently. None of the methods used will have a negative effect on engine life. If your engine requires a higher octane fuel, it will run better and get better milage. If not, you will notice nothing different between the grades.
I also owned a GTI with the 1.8T about 20 years ago. That engine was rated to run 87 but made a bunch more power if running premium. So I ran premium.

E85 may be safe for many vehicles. If they are designed for it, the fuel system will not be harmed by it. However, I know of no data that says it is better for the engine. Only data that says it will not harm it.
E85 is NOT environmentally responsible. It is NOT renewable. It is NOT good for our economy. It is good for the farmers who are able to get the subsidy.

 

Got almost 480K in a 2011 that has never had anything but 87. No knock ever.

 

My 2cents about ethanol. In my prior profession 2001 to 2015, I sold lawn and garden equipment, ethanol usually destroyed the carbs in three years if the customer did not drain the fuel system every season and used E10 or E15. Lived in southern MN at the time, corn feilds everywhere, so ethanol was the best THING to get( propaganda?? Maybe). Fuel mileage story-- we had a flex fuel town and country so I filled in Sioux Falls with E85 because it was about about 1.50 less per gallon. Our mileage driving back to MN, went from 24mpg to 14 mpg on the instant mpg readout and verified by pen and paper. Ever since then, I won't put e85 in anything and only run real gas in my tundra and my wife's highlander