Fuel Octane ratings. Do they really matter?

[Jay1990]

General consensus is more people on the forum so far use higher octane stuff than normal.

Standard cars probs wont see as much benifit as mapped cars but a lot is talked about on the "cleaning properties" of these more expensive fuels.

This picture is carbon buildup/oil? on the inside of the head of a 1.4TSI. I think this has more to do with oil consumption/misfire issues but would higher octane fuel slowdown/prevent this kind of build up better than regular jungle juice?


Discuss

EDIT: also, as a P.S why is it that one or two cylinders get more caked in the black stuff here than others, from left to right it seems to get "better"
Jay

 

[NetworkMan]

but would higher octane fuel slowdown/prevent this kind of build up better than regular jungle juice

I've never seen any evidence for the claimed superior 'cleaning properties' of more expensive petrol - just hype from the ad-men!

 

[lucifer666]

Where did you get this pic from? Think carbon build up is every engine. Misfiring would make worse the problem. Oil consumption is down to dodgy rings. And the reason that one side is better than other is because of common rail fuel supply. Often cylinders 3 and 4 are starved of fuel under high intensity use/ heat/ misfiring with the old code and 1&2 are overfuled. Make sense? Seat released a uprated pump to try and solve this symptom of a different problem

 

[Nutkin]

I've never seen any evidence for the claimed superior 'cleaning properties' of more expensive petrol - just hype from the ad-men!

I've seen it in stripping down engines, it is not hype it works.

 

[NetworkMan]

I've seen it in stripping down engines, it is not hype it works.

Show us then.

 

[secret.squirrel]

Where did you get this pic from? Think carbon build up is every engine. Misfiring would make worse the problem. Oil consumption is down to dodgy rings. And the reason that one side is better than other is because of common rail fuel supply. Often cylinders 3 and 4 are starved of fuel under high intensity use/ heat/ misfiring with the old code and 1&2 are overfuled. Make sense? Seat released a uprated pump to try and solve this symptom of a different problem

The old 2ltr Boxer engines in the old Imprezas were similar, only the close cylinders weren't over fueled, but the cylinders further along the rail ran lean. If I remember rightly the solution was higher capacity injectors and an uprated fuel pump, and all was solved. Has this been much of a problem on the TSi engines though? Would the uprated pump/injectors make any significant difference to justify the cost?

Squirrel.

 

[Jay1990]

Where did you get this pic from? Think carbon build up is every engine.

And the reason that one side is better than other is because of common rail fuel supply. Make sense?

"stolen" from a workshop. lol. It was on the internet somewhere.

ahh okay. These days you would think that they could flow the same amount at the same time somehow.... Corsa's melt Piston 1 through not flowing enough fuel so one would assume fuel rail is on the other side?

Show us then.

The picture above I got is one of the very few from inside workshops ect. Dealers/Manufactures dont want this stuff coming out. So I imagine there is a strict policy of no show and tell and it would be risking Nutkins job for him to show pictures ect

Jay

 

[NetworkMan]

You'd need two identical engines, one run on normal petrol, the other on the fancy stuff, under exactly the same conditions. I've never seen anything like this anywhere. There are so many variables that you couldn't prove anything under normal conditions.

 

[Jay1990]

I was going to say that there are many varibles so would be very difficult to say. As much as I agree that "ad men" have lots to do with it and marketing plays a major role in everything btu they cant sell something without some evidence that it does something different. Remeber when Coke did that water that was just practically tap water and it got shot down. Where as Evian is still going strong because there is some difference to tap water, differences, may be negligble but in certain conditions im sure the water and the petrol are different.

Jay

 

[Nutkin]

You'd need two identical engines, one run on normal petrol, the other on the fancy stuff, under exactly the same conditions. I've never seen anything like this anywhere. There are so many variables that you couldn't prove anything under normal conditions.

Well we do exactly those tests so there ya go.

 

[Jay1990]

Nice work. You seem to do all sorts of testing in your line of work.

Any statistics/figures on the differences that can be shown?

Jay

 

[FR_POWER]

Owing my car for 2 years and abit, I've used every single petrol station where I live.

From supermarkets to big brands I.e shell BP etc

I've only used v power and tescos super unlead thing, couple of times but I've been using normal unlead all the time. I had no misfire problems.

 

[Jhouse_101]

I put the 97 from Total in mine. No complaints, can't say iv noticed the car run better than on 95 mind...