Shell V-power Nitro+

[jetboy]

So Shell launched it's new "performance fuel" the other day. Dunno if you use Knock Index or Octane rating but they lowered the octane rating from 99 to 98 and added some other stuff that's "good for your engine". By coincidence, I tanked up on the stuff and felt that my car was a little more spiffy. Did any of you try this or your equivalent fuel?

It's probably just a placebo effect. I know the previous owner swore by 95.

This whole situation made me remember something about the ECU "learning" the fuel in some way? I tried searching but came up with nothing, do any of you remember the thread(s) on that topic?

[LastSVXintheChi]

Originally Posted by jetboy

So Shell launched it's new "performance fuel" the other day. Dunno if you use Knock Index or Octane rating but they lowered the octane rating from 99 to 98 and added some other stuff that's "good for your engine". By coincidence, I tanked up on the stuff and felt that my car was a little more spiffy. Did any of you try this or your equivalent fuel?

It's probably just a placebo effect. I know the previous owner swore by 95.

This whole situation made me remember something about the ECU "learning" the fuel in some way? I tried searching but came up with nothing, do any of you remember the thread(s) on that topic?

in Europe do you guys get more than 3 types of fuel? sorry i know its a little off topic but i know we dont have a 98 octane fuel.....just curious

[dragoontwo]

Originally Posted by jetboy

Dunno if you use Knock Index or Octane rating

We use AKI or Anti Knock Index here.

Originally Posted by LastSVXintheChi

we dont have a 98 octane fuel

Next time you fill up, take a look at the labels for the different grades. You'll find no Octane rating.

[jetboy]

Originally Posted by LastSVXintheChi

in Europe do you guys get more than 3 types of fuel? sorry i know its a little off topic but i know we dont have a 98 octane fuel.....just curious

I think you can find 91 or 92 if you really go looking, 95 unleaded is standard and then 98 is more premium. Shell used to have 99 for their V-Power but switched to 98 when launching Nitro+.

Again, was there something about the ECU "learning" and a need to reset this in order to utilize a better fuel properly?

And, did you try Nitro+ and pass judgement?

[dcarrb]

No expert here, but I don't believe the ECU can learn to derive any benefit from a fuel with an octane rating higher than specified by the manufacturer. High octane does nothing for performance.

dcb

[LastSVXintheChi]

Originally Posted by dragoontwo

Next time you fill up, take a look at the labels for the different grades. You'll find no Octane rating.

in IL they have an octane rating...i think they are 87 89 and 92...i could be a little off but i KNOW for a fact there are numbers here

[RallyBob]

You have to take into consideration that in most countries east of the Atlantic they rate gasoline octane by RON only.

In the US gasoline is rated by RON + MON/2.

So in other words, US 93 octane is very similar to 98 octane overseas.

[jetboy]

Originally Posted by dcarrb

No expert here, but I don't believe the ECU can learn to derive any benefit from a fuel with an octane rating higher than specified by the manufacturer. High octane does nothing for performance.

dcb

So no difference if it's 95 or 98, really? 95 is cheaper

[LastSVXintheChi]

Ooooooo ok that explains a lot

[immortal_suby]

A simple explanation:

The ECU is going to try to advance the timing until it senses knock. Once knock is detected, the timing is retarded.

Lower octane = more prone to knock (pre-ignite)

Deposits in your combustion chamber (on valves, pistons) increase the chance of knock - in this case a fuel octane rating higher than the manufacturer specifies could actually restore performance by allowing more advanced timing than the prescribed fuel would. A good fuel system cleaner might be able to do the same thing.....

[dcarrb]

Originally Posted by immortal_suby

A simple explanation:

Deposits in your combustion chamber (on valves, pistons) increase the chance of knock - in this case a fuel octane rating higher than the manufacturer specifies could actually restore performance by allowing more advanced timing than the prescribed fuel would.

Yep. I ran premium exclusively in an old high-mileage Legacy because its engine otherwise rattled under load like a runaway freight car.

Still, folks need to realize that in general terms, higher-than-prescribed octane does not equal better power/performance/economy; it just thins your wallet.

Earlier this year (just when fuel prices were beginning to spike), some alleged authority interviewed for National Public Radio's Morning Edition flatly asserted that using premium gas would improve fuel economy. Many listeners contacted NPR to refute the claim, and they aired a retraction the next morning.

dcb