V8 Weird Engine Noise

[JB.]

It's the statement about improved performance - and the change from that in the '07 manual - that I found interesting.

 

[truckmike26]

Going off on a tangent here: always being a car guy, I remember talking about this subject with different Toyota owners (Corollas, Camrys, the first-gen MR2, trucks, etc.) over the past 20 years. And this is purely, purely subjective but many times modern, electronically-controlled Toyota engines do respond favourably to higher octanes. Not that they need them -- they run fine on regular. And not like there are big gains -- a few hp and lb-ft. One thing to promote endless discussion: my neighbour who has an '07 Corolla said he felt stronger acceleration with 91 octane over 87 octane but that went away using Sunoco 94 octane. Maybe there's a sweet spot, not more is better but the right level is better.

 

[2UZ]

I only use V-Power. I remember finding a Toyota document noting the difference in performance between regular and premium gas and it was more than negligible.

 

[rebelbowtie]

I only use V-Power. I remember finding a Toyota document noting the difference in performance between regular and premium gas and it was more than negligible.

the stock fuel and spark trims are not adjusted to take advantage of higher octane fuel :dammit: if we are talking about a high compression engine or a turbo charged engine thats what thing and this is not that.

 

[2UZ]

the stock fuel and spark trims are not adjusted to take advantage of higher octane fuel :dammit: if we are talking about a high compression engine or a turbo charged engine thats what thing and this is not that.

TOYOTA WOULDNT SAY IMPROVED PERFORMANCE WHEN USING PREMIUM GAS IF IT WASNT THE CASE.

93 pays for itself every tank with improved mileage. What is it? $5 a tank. That's nothing in the grand scheme of things.

 

[rebelbowtie]

TOYOTA WOULDNT SAY IMPROVED PERFORMANCE WHEN USING PREMIUM GAS IF IT WASNT THE CASE.

93 pays for itself every tank with improved mileage. What is it? $5 a tank. That's nothing in the grand scheme of things.

its all smoke and mirrors, IF and i say IF you had an engine tuned to optimize benefits of higher octane fuel such as 91 or 93 then yes using lower octane would lower your fuel economy and power output. this is not he case with the 2UZ-FE since it is tuned for 87 octane fuel.

 

[2UZ]

its all smoke and mirrors, IF and i say IF you had an engine tuned to optimize benefits of higher octane fuel such as 91 or 93 then yes using lower octane would lower your fuel economy and power output. this is not he case with the 2UZ-FE since it is tuned for 87 octane fuel.

You don't have 100% documented proof. Only a stated minimum octane rating. The 2UZ is a third world engine that *can* run on the cheapest gas around. When testing, I got 2mpg better economy and noticeably better performance using premium fuel.

 

[rebelbowtie]

You don't have 100% documented proof. Only a stated minimum octane rating. The 2UZ is a third world engine that *can* run on the cheapest gas around. When testing, I got 2mpg better economy and noticeably better performance using premium fuel.

you have your butt dyno, do you know how many variables could have gone into those 2mpg?

 

[2UZ]

you have your butt dyno, do you know how many variables could have gone into those 2mpg?

I'm sticking with 93. Always.

 

[Mark86]

I will listen to you and stick with premium. The knocking only occurs on heavy acceleration and I hear it very infrequently. Maybe I will switch back to Hess or Sunoco.

 

[NJshadow93]

I've honestly never fed my 2UZ anything but regular, and it has amazing power. Maybe next time I'll try premium so I have something to compare it to.

 

[JB.]

On the other hand, regular gas that arrives from the refineries (mostly on the gulf coast, for us eastern US folks) by pipeline can have up to 5% of anything in it that will burn, maybe more. Typically diesel, bunker fuel, or kerosene (jet) 'transmix' gets added. That's how they deal with the off-spec interface between two dissimilar batches. Premium gasoline is protected from this type of thing.

Interesting stuff. My radar is always on the lookout for potential nuggets like this.

Do you work in the industry?

If I'm reading your post the way I think I am, I'm guessing you use premium.

 

[Atlanta_man]

Yes, I work for the pipeline that delivers 60% of the refined products used on the east coast. I buy the cheapest regular I can get.

 

[boondoggle]

I've been told there is usually little to no difference between fuel brands.

Since in most areas there are only a couple of refineries (based on population, I guess) one fuel tanker will likely service several different gas stations. The only difference being a splash of propietary additives.

They're all sharing the same pipelines and refineries. They all have to use additives/detergents - a government requirement since 1994. So, really I don't think there is any benefit to buying more expensive gas all Octane levels being equal.

 

[JB.]

Yes, I work for the pipeline that delivers 60% of the refined products used on the east coast. I buy the cheapest regular I can get.

Thanks

 

[FireTruckGuy]

What still kind of surprises me here is that if the engine hears audible pinging it should dial back the timing to effectively reduce it. Why is this not happening? I am assuming that these engines use knock sensors but I could be wrong. If anyone wants to know what pinging does to an engine, I have a jar full of parts I can show you. I also am assuming that there is a MLS type gasket between the head and the block. Which can withstand the extra cylinder temp and not blow out the gasket between cylinders. The bad part is it keeps all the fun that is happening in the cylinder localized and will eventually burn a valve or a piston. What might be going on and this is just speculation, is that running premium with the added detergents or whatever they may put in it, that the valve are slowly burning off deposits and the noise is actually the valves finding new homes in their seats that they havent seen in awhile. When I worked for Ford the Probes had a hard time with valves not find their seats. We would run what is similar to Seafoam in them and the problem went away. Have you ever run Seafoam through your intake? You may want to try that. I have run 87 since I bought mine and have never had pinging. I listen for it every time I hit the highway and that is every morning.

 

[eli_lilly]

Although the thread is months old, FireTruckGuy is right. Either that batch of gas was bad or something else is wrong. Makes me think of that other recent thread where the guy's brakes were sticking.

-E