[tango131]

Apologies if this was covered before, but I was watching yesterday’s episode of 5th Gear on BBC America (the one where they test the Toyota/Scion FT-86, Kia Sportage, and Tiff races a Lambo in the Lambo Cup), and saw a very interesting report on whether premium gasoline (petrol) produces more power than regular gas, at least for UK gas.

They tested shell v- power 98 ROM = 93 premium in the US, BP ultimate 97 RON ~ 91/92 premium in the US and 2 “regular” non premium gasolines. They tested the gas on a 2.0 turbo GTI and a dyno (rolling road for you Brits) and had rigs to switch between gas types w/o contaminating or having left over gas in the tank. The results were that the Shell v- premium made about 5 HP more on the dyno to the wheels. I find that a significant result just by using good gas. See a screen shot pic of results. I have no idea if the gas sold in the US would have a similar formulation, but I would hope so. Esso (Exxon/Mobile in the US) premuim gas also had close to a 5 HP advantage over regular gas.


Back when I had a turbo Subaru I could swear that I felt the car ran stronger on shell V-power, but had no proof. I’ve been using v-power since. I theorize that premium gas has a greater effect on turbocharged cars as the cars computer can slightly adjust timing and boost to make more power. As our X3’s are all turbo now (and the X35 since 2011), I figured to pass this along. I know I’ll continue to use shell v-power 93 (US RM/2) on all my cars.

[rmeir]

all i know is mine runs better on shell and i get better mileage

[paul386]

There are so many things at play here that it would be super difficult to actually determine what is causing the power change. In the United States of course, we all have to subsidize the farmers and burn low energy / high pollution / high price ethanol.

The one thing I do know for certain. Octane rating does not change the energy content in the fuel.

[HighlandPete]

Originally Posted by paul386

The one thing I do know for certain. Octane rating does not change the energy content in the fuel.

Our engines have knock sensors, so the higher octane fuels will allow for more advanced timing and therefore (in most cases) more efficient power development.

Most BMW engines are rated on the higher octane fuels, for output and fuel economy. Certainly my N55 535i engine is, as is stated in the UK BMW brochure.

Older brochures used to say something like the following (for the UK market). "The 6-cylinder and 8-cylinder petrol engines are designed for RON 98 fuel. They may be run on fuel down to RON 91 with a slight decrease in engine power and an increase in fuel consumption".

HighlandPete

[carlili4190]

Originally Posted by paul386

There are so many things at play here that it would be super difficult to actually determine what is causing the power change.

+1

[car_fan]

As a matter of habit I always run Shell V-power and have done so for years.

[HighlandPete]

Originally Posted by paul386

There are so many things at play here that it would be super difficult to actually determine what is causing the power change. In the United States of course, we all have to subsidize the farmers and burn low energy / high pollution / high price ethanol.

The test, here in the UK, was switching fuel only. Can't see what else is coming into play except the fuel itself, and the ECU adapting to the knock rate. OK, the fuel additive package could be different, as it often is across brands, but the HP change is from switching fuel and octane rating. All fuels would have been to the same British Standard.

One of our tuning companies (Thorney MotorSport) also ran some extensive dyno tests on different fuels. A tuned BMW M3 CSL showed a 40HP gain running on RON 99, compared to the standard RON 95 fuel. Other less tuned engines (with knock control) also showed consistent improvements in HP, as the octane rating was increased.

HighlandPete

[tango131]

Originally Posted by HighlandPete

The test, here in the UK, was switching fuel only. Can't see what else is coming into play except the fuel itself, and the ECU adapting to the knock rate. OK, the fuel additive package could be different, as it often is across brands, but the HP change is from switching fuel and octane rating. All fuels would have been to the same British Standard.

HighlandPete

exactly. they only changed the gasoline and listed the average dyno (rolling road) reading of 3 separate pulls per type of gasoline.

fifth gear won't let us in the US view the vidoes on their website. perhaps someone fromthe UK can post the episode video.

[HighlandPete]

Originally Posted by tango131

exactly. they only changed the gasoline and listed the average dyno (rolling road) reading of 3 separate pulls per type of gasoline.

fifth gear won't let us in the US view the vidoes on their website. perhaps someone fromthe UK can post the episode video.

Seems since Fifth Gear has be pulled from TV, even over here we have issues accessing their episodes/videos.

Does this link?



HighlandPete

[tango131]

Pete, that video works, but it is not the episode I saw a few days ago, which used a new white GTI 2.0 turbo

[HighlandPete]

Try this one.



HighlandPete

[tango131]

^^^

that is it indeed. thank you