[Stone Axe]

Almost all modern fuel injected cars over the last decade or two automatically adjust the fuel/air mixture and spark timing based upon feedback from their various oxygen sensors and such.

In my experience with my last 4 cars higher octane fuel produces a tad more more power and tad better mileage. In my Subaru the mileage improvement was negligible and did not cover the additional cost. But in my Suzuki premium gas made a significant difference and it was worth the cost.

What confuses me is that the owner's manual states that the VT is designed for 87 octane only - which is weird because every other car I've had said 87 octane was fine but premium gas would perform better. But then the quickstart guide says it is designed for 87 octane gas or higher - but does not claim any benefits from it.

 

[anticmos]

I have a station nearby that sells 110 (or something ridiculous like that) for the racers... Lets give that a spin! I'll let you know how it went before detonation.

It is my opinion, which is similar to most everyone else here, that one isn't going to see or feel much of anything from increasing octane up to 93 without any ecu mods. Yes, with the higher octane, top-tier fuels, consistently used over the course of many years, one may discover that their motor is still performing at higher levels than a motor that has always burned 87 octane, BUT the costs associated with the higher octane, would be greater than the replacement costs of fouled components.

The only gains, again my opinion, we can see without mods, would be found by using non-ethanol fuels. This will result in better mpg and "performance". BUT we would NOT be increasing HP, we would only be allowing the motor to perform at an optimal output. Ethanol is trash & only increases wear and decreases performance. Even our manual says to use the lowest "blend" % possible. Of course the price difference for "pure" vs. blend is still a hard choice to make. You're individual driving style will determine if your gains outweigh the price difference.

I will always recommend running at least one tank of "pure" (non-ethanol) about every 3k miles, and drive that tank hard, to help reduce the build-up from ethanol-blend fuels.

Maybe my ramblings are useful to some?

 

[[email protected]]

the increase wear is a myth.. and decreased performance? Where do you get that from.. the ethanol is bad on old cars that use different fuel lines, most new cars wont have a problem with the ethanol. as far as decreasing the performance.. the point of ethanol is to effectively increase the detonation barrier and lower the cost of the gas. Ethanol actually has a much higher power potential (effectively like 103 octane iirc) then standard gas, between detonation resistance and cooler burning temps e85 is the way to go for people who want top performance and reliability. As long as your car isn't sitting for extended periods of time the ethanol will not hurt anything. Not to mention on a standard port injection car, ethanol helps keep the valves cleaner then full gas. YES full gas will give you better mpg, ethanol is approximately 28% less efficient then standard gas.

as far as this whole thread.. it's a moot point unless we know about the inner workings of the ecm.. many new cars have high and low octane tables so they can pull timing if there is issues with the gas. unless your going from shitty 87 to top tier 93 you probably wont notice anything on the butt dyno. but the people saying ZOMG IT SAYZ FILL IT WITH 87 THERE'S NO WAY ANYHING ELSE CAN HELP YOU.. are being just as silly as the people thinking higher octane is going to make a noticable difference. But since we don't know how the ecm is setup. everyone is wrong and no body is wrong.

 

[Franky]

I have my VT since mid august and I have noticed a huge difference between regular fuel 87 (from top tier gas providers) vs premium 91 (top tier also). The boost on the car is more noticeable on premium 91 then regular 87. Every time is decide to fill it up with premium I see the effect right away.

I cannot tell on the MPG but it is much more fun to drive using premium gas.

 

[Turbosocks]

I can do some logs to see if the boost is any different between premium and regular fuel. I can compare the timing also. Should see a noticeable difference if in fact it is adjusted based on the fuel grade.

 

[[email protected]]

I can do some logs to see if the boost is any different between premium and regular fuel. I can compare the timing also. Should see a noticeable difference if in fact it is adjusted based on the fuel grade.

thats what I was gonna do .. as well lol

 

[Turbosocks]

good luck doing it first

 

[[email protected]]

good luck doing it first

haha if i do i'm gonna be disappointed in you lol.. however I might be able to post up easier to read data then you

 

[Stone Axe]

It has been about 20 years since fuel injected engines needed to be calibrated for octane. The VT, like all modern cars measure the amount of oxygen in the exhaust to determine fuel/air mixture and sense pre-detonation to determine ignition timing.

Higher octane fuel allows for leaner mixtures and more advanced timing which means more power and better mileage. It also contains less carbon impurities so it leaves fewer deposits.

But Hyundai threw away the rule book with the VT engine. 125hp per liter, 38mpg, 100,000 mile warranty and it is designed to run 87 octane. That is so far beyond what any other engine can do that I don't what to think anymore.

Once my VT is broken in I will do what I always do, run a few different types of fuel through it and do the math.

 

[Ralpho]

Talked with some dealer techs when I recently purchased my 2013 turbo. Makes no difference whether you put 87 octane or 93 octane. Car will run the same either way. Only difference will be in your wallet. Only fluid recommended as we all know with turbos is using the proper oil with your changes.

 

[Turbo 'ToonSter]

You mean regular old Dino oil? That's what the techs here say to use.

 

[Ralpho]

Either way. The older Turbos demanded synthetic oil. The newer ones are not as reliant on either dino or synthetic but they were more concerned about the weight of the oil. Much could be argued either way for the type but they were more concerned with the weight of the oil. Now 5W30 is good for the regular engine but they dont recommend other other than 5w30 or 5w40 for the GDI Turbo. Looking at the owners manual I now realize that perhaps they cannot say much more than that or risk running against the advice of the manufacturers recommendations.
As a personal preference for higher revving engines Mobile 1 or similar blends are better. And again, much could be debated to the benefits.

You mean regular old Dino oil? That's what the techs here say to use.

 

[1.6 T-GDI]

For what it's worth, the official Veloster Twitter account said it's designed to run on 87, but you can get increased performance from 91 mid-grade.

We have 89 mid-grade here, then it jumps to 93.

 

[[email protected]]

For what it's worth, the official Veloster Twitter account said it's designed to run on 87, but you can get increased performance from 91 mid-grade.

We have 89 mid-grade here, then it jumps to 93.

so by proxy you should technically get a smaller bumper from 89. 93 would probably give you the same bump as 91.. looks like I'll be running 91 just like I planned no doubt. I will however try to do some data logs with both to see AFR and timing curves

 

[Boots Ylectric]

I'm curious to see the logs on this. I can't see mileage or power increasing enough to justify the extra 25 cents a gallon.

 

[vtlover67]

I'm curious to see the logs on this. I can't see mileage or power increasing enough to justify the extra 25 cents a gallon.

IMHO, it is not worth paying more for full gas (non-ethanol), or even getting a higher grade of E10 gas, when there is really not much to gain. Just fill her up with regular gas, the cheaper the better, and spend those savings in getting her better headlights, or interior lighting, or better yet, a nice trip to show her off. I am so happy that I can just put the cheapest gas in town and go on my merry way!!!!

 

[Boots Ylectric]

IMHO, it is not worth paying more for full gas (non-ethanol), or even getting a higher grade of E10 gas, when there is really not much to gain. Just fill her up with regular gas, the cheaper the better, and spend those savings in getting her better headlights, or interior lighting, or better yet, a nice trip to show her off. I am so happy that I can just put the cheapest gas in town and go on my merry way!!!!

Same here. Years of putting premium in my Acura I get giddy every time I see the price on regualr 25-30 cents cheaper lol

 

[[email protected]]

I'm curious to see the logs on this. I can't see mileage or power increasing enough to justify the extra 25 cents a gallon.

imo saving 3 bux a fill up isnt enough to warrant me not making a few extra hp lol I mean hell I run e85 in my dd lol it's "free" hp to me .. but thats just me

 

[Stone Axe]

The bottom line will be when there are enough VTs that have more than their break-in mileage on them and buying premium yields more mileage than the extra cost of the gasoline.

The VT makes enough power for me that the only question I have is whether or not premium gas gets me enough additional mileage to justify its cost.

 

[[email protected]]

The bottom line will be when there are enough VTs that have more than their break-in mileage on them and buying premium yields more mileage than the extra cost of the gasoline.

The VT makes enough power for me that the only question I have is whether or not premium gas gets me enough additional mileage to justify its cost.

fair enough