silly wife

catflea

johnfarquhar74 wrote: »

I've heard that can be quite damaging to your wallet! I assume you mean one of those sooper dooper high octane performance fuels that some people 'swear' gives their 1.1L saxo's better performance?

This was a 1.3 Fiesta, it did "feel" more responsive, and I swear I got better mileage, but without the facts and figures its not worth the bother...

Strider590

catflea wrote: »

This was a 1.3 Fiesta, it did "feel" more responsive, and I swear I got better mileage, but without the facts and figures its not worth the bother...

You'll get better mileage because the fuel is purer, not because of the Octane rating.
What people don't understand is that Octane ratings are more to do with ignition timing because higher octane fuel burns at a different rate.... It does not equate to more power unless your petrol engine needs that fuel to run, in which case 95ron will damage the engine anyway.
Also, Jap imports should never be run on 95ron unleaded..... As they're built/designed for high octane, high quality fuel.

On this note, it's worth mentioning that supermarket 95ron unleaded gives poorer mileage than big brand 95ron, because the supermarkets use inferior additives to cut down costs and increase profit.

catflea

Not sure that would make any difference to a single port injection system really....

mkirkby

Strider590 wrote: »

Also, Jap imports should never be run on 95ron unleaded..... As they're built/designed for high octane, high quality fuel.

On this note, it's worth mentioning that supermarket 95ron unleaded gives poorer mileage than big brand 95ron, because the supermarkets use inferior additives to cut down costs and increase profit.

The Jap import impreza I used to own ran fine on 95 octane because the ECU was capable of reprogramming the timing for lower octanes. I would suggest that unless you get a high performance older import, there won't be a problem as modern ECUs will be designed to cope with any detonation. That's why the engines have knock detectors in the first place. As mentioned though, older imports might not be able to do this.

As for supermarket petrol, have you found a report that says it's definately inferior? I wouldn't have thought it would be worthwhile producing mutilple batches of 'normal' 95 RON unleaded for different outlets.

This item from What Car seems to back this up:-
http://www.whatcar.com/car-news/what-car-q-and-a/is-supermarket-diesel-inferior/217130

"According to the Petrol Retailers' Association, there is no difference between the standard petrol and diesel that you buy from either a franchised fuel station or a supermarket forecourt. In many cases, the fuel is sourced from the same refineries and sometimes delivered in the same tankers."

Have found a test online which shows different results?

Strider590

mkirkby wrote: »

"According to the Petrol Retailers' Association, there is no difference between the standard petrol and diesel that you buy from either a franchised fuel station or a supermarket forecourt. In many cases, the fuel is sourced from the same refineries and sometimes delivered in the same tankers."

Have found a test online which shows different results?

It is the same fuel, from the same refinery in the same tankers. The additives are added at the individual petrol stations.

Primarily these additives were to increase fuel octane to meet the required standards, when leaded fuel was stopped they had to add chemicals to raise the octane levels so that cars could continue to run without detonation..... But then because this additive left residues in the fuel lines, carbs/injectors etc, they had to add detergents to combat this. Fuel injectors don't like this stuff, once a build up starts and the injectors spray pattern is affected your performance and fuel economy will drop noticeabley.

The quality of the overall additives does vary from retailer to retailer and although I do use it, I wouldn't recommend extended long term use of supermarket fuel without the occasional use of good quality "over the counter" fuel additives.....

skiddlydiddly

I too have a Jap import(pulsar) and it runs crap on 95 ron.The ECU can compensate but it does this by retarding the ignition and reducing power.Whats the point in having a car like that if you are going to ride around with less than its supposed to have?
I have always filled up with 97+ron and octane boosters and it runs so much better on that and is noticably quicker too.

Strider590

skiddlydiddly wrote: »

I too have a Jap import(pulsar) and it runs crap on 95 ron.The ECU can compensate but it does this by retarding the ignition and reducing power.Whats the point in having a car like that if you are going to ride around with less than its supposed to have?
I have always filled up with 97+ron and octane boosters and it runs so much better on that and is noticably quicker too.

I've got a Westfield SEI 1650 711m crossflow, with 1300 pistons and a compression ration of 11:1, on 95ron it'd chew the pistons up and spit them out in tiny pieces in less than 50 miles. :rotfl:

mkirkby

Strider590 wrote: »

The quality of the overall additives does vary from retailer to retailer and although I do use it, I wouldn't recommend extended long term use of supermarket fuel without the occasional use of good quality "over the counter" fuel additives.....

Ah... point taken & thanks for the info. I guess the 'additive' route is the only way the normal petrol chains can compete with the supermarkets. Higher price but better additives for better quality.

property.advert

You think you have problems ! My missus has never had to fill up with fuel as in her country they still have people to do it for you ! Can you imagine sending her to the garage to get it filled up ?

mkirkby

skiddlydiddly wrote: »

I too have a Jap import(pulsar) and it runs crap on 95 ron.The ECU can compensate but it does this by retarding the ignition and reducing power.Whats the point in having a car like that if you are going to ride around with less than its supposed to have?
.

What's the point indeed.

In reality I only ran my Impreza on 95 octane when I had to suffer a major wage decrease. I sold it soon after. Probably because I had to "ride around with less than its supposed to have" !

Should have thought that one through before posting really