E-Free / Premium Fuel impact on performance

There have been countless threads on fuel types, but hang with me - this one is different.

I started experimenting with different fuel types a few tanks ago. Started running ethanol free and for the first couple of tanks I felt like it was the holy grail. Vibes reduced, shifting smoother and my MPGs went up by 15% at least. When I couldn't get ethanol free I ran some Vpower and I've always put Top Tier in the tank.

One day I started to notice heavy engine vibration and, at times, it felt like the power steering wasn't even working when hitting bumps and uneven pavement - steering would harshly jerk. Of course the dealership couldn't help, so as part of my process of elimination I burned through the VPower I had in the tank and refilled with mid grade. The detonation-feeling vibes in the steering wheel (while still present) suddenly were not as harsh and my power steering feels more normal.

So the question is, why would (or can) higher octane or 87 E0 fuel cause these sort of symptoms? It almost felt as though the engine couldn't adjust the ping sensors and power the steering... Is this a sign of something bigger wrong with the engine if the truck won't operate properly on E0 or 92?

 

Do you usually get gas at the same station? Is it possible the tank(s) you get premium from are compromised?

 

This could be part of the problem

 

It shouldn't have to adjust the "ping sensors" for higher octane fuel.

 

I normally get my fuel at one of a couple of different Shells when home but spent a lot of weekends in the mountains a few hours away so have definitely had some variety but always use Top Tier fuels

Anything is possible I suppose but I did some experimenting in between tanks and filled up 1/2 the tank with mid and the vibes reduced but still much heavier than before the higher octane experiments. Came across a top tier BP with E0 and filled up while out of state and the strong vibes returned almost like I literally could feel every detonation. I did some switching to ensure it wasn't simply my imagination and I'm sure there could be and entirely different reason but that's the only variable that I've changed and the performance impact is highly noticeable.

 

I've been e free fuel for maybe last 10k miles. I have none of the issues you refer to. Some of the e free I get is 90, other is 87. No issues.

 

You should get better MPG with ethanol free gas. Ethanol is pretty has about 15% less energy per gallon when burned.

Higher octane gas will have less MGP vs EO gas for that reason. Ethanol just reduces MPG.

As for the rest of it....You have something wrong with your truck and it has nothing to do with the gasoline you use, unless you got a tank of bad gas.

 

That's kinda odd for sure. Makes me think you got bad gas, but I don't know. I run e0 exclusively, it's only available in 87 octane, non top tier. I have none of those issues, no chirping, and get better gas mileage with what I run. I use redline si1 since it's non top tier. You may need more than 1 tank to let the ecu compensate for what gas you use.

 

Wonder if the intake could be an issue? Couldn't airflow have an impact?

Yeah, that's the more likely assumption. I ran a couple of different tanks of gas from different locations with similar results. Definitely something (or many things) wrong with my truck... getting no where with Toyota or my dealer. such a love / hate relationship with this truck. I just want to enjoy driving it consistently

 

I've never heard someone be able to relate fuel type to power steering. Those are some real mental gymnastics.

 

Do you have a different induction system on your truck? If so, what is it?

 

Nope, all stock

 

Believe me, I know... probably completely unrelated but it's the only variable that changed...

 

It's likely your power steering pump is either clogged or on its way out, or perhaps your steering rack is going. Your experience with e-o and premium fuels are likely just a coincidence.

 

Yep, definitely odd and likely a coincidence. Like I said when I first out E0 in the tank it ran like butter initially, then eventually started vibrating like crazy until I moved back to midgrade E10. Maybe engine mounts, and agree likely unrelated to power steering

 

I remember about a few months ago getting 27mpg on Highway with E0 fuel, during a road trip through Utah/AZ and Never experienced any of the symptoms you expressed. Not sure bud.

 

It's not possible for your fuel octane to effect your steering. These are two separate systems. The steering issue could be different road conditions?