Noticeable change , Tesco Momentum , to Shell reg-saver ?

[AGB-S3]

Noticeable change , Tesco Momentum , to Shell reg-saver

have used tesco-m for a while , decided on a change and Filled up , with empty tank, with shell regular - fuel saver .

Seemed to have a noticeable increase in low end power , bit unexpected , or to be expected ?

standard map that sensitive to fuel changes ?

G,

 

[Tj 0785]

I would of thought it would of been the other way round Tesco momentum and shell v power are the best fuels. Placebo maybe ?

 

[AGB-S3]

Its not the V power , just the standard , but the ave mpg is up as well on the clock ... i thought it was odd ,

 

[Stuart B]

even the S3 manual suggests you use super unleaded at least once in every 4 tanks, I burnt my sparkplug the day I picked my car up from using normal unleaded.

 

[<tuffty/>]

The ECU can cope with a degree of variance in octane and fuel quality (which affects octane)... higher octane is key to knock suppression... knock suppression is key to managing timing advance... timing advance is free power...

Lower octane fuels will have very little effect off boost... on boost is where the benefits are... the ecu will be attempting to meet the requested timing advance of the map which if you have a stage 2/custom map designed for 98/99 octane it will never achieve due to knock... so the ECU will pull timing and the engine will feel 'flat' as you lose torque...

The other side affect of lowering the timing advance is higher EGTs...

So... in conclusion... std map is designed to cope with varying fuel quality but its still optimised for 98ron... its designed to run 95ron in case you are caught short and thats all thats available...

Running lower octane fuel on a mapped engine that is more optimised for higher octane fuels will still work but the reliability window is a lot narrower and the ECU will pull more timing than it would as std...

EGT's will increase when timing advance is removed... this will mean EGT protection kicks in sooner and the engine will generally run hotter...

Drive a 'performance' car, buy the right fuel... its that simple...

<tuffty/>

 

[AGB-S3]

I was thinking more on the lines that Mr T ''every little helps'' , may extend to the odd splash of pink paraffin or silicone in the fuel .. may be in this case , the shell was a step up , what struck me was torque at low rpm . see what happens at the next fill up . . . unless shell have developed a burn modifier ..

 

[<tuffty/>]

Its more likely that Shell 95 is simply a better quality fuel despite momentum being classified as 99 ron... see it all the time on the dyno...

<tuffty/>

 

[hydro s3]

So what fuel do people recommend?
I use super unleaded since that was the fuel it was mapped on. I haven't saw any problems with it.

 

[<tuffty/>]

The term 'super unleaded' is a bit ambiguous as that potentially covers all fuels over 95 ron...

The most consistent fuel for results I have seen on Bill's dyno is Shell V-Power... super market fuels will vary as they tend to get it from various suppliers... I can't speak for BP or Esso fuels as we don't really have many stations round where I live and most people that come to Bills will use the Shell station just up the road before turning up...

If you use the fuel it was mapped on then it should be as good as it was ... if you had it mapped on V-Power then used A N Other fuel then there is no guarantee that performance will be the same...

I personally only use Shell fuels in both my A2 (normal derv) and S3 (V-Power)...

<tuffty/>

 

[Stuart B]

All I find is... if I put in shell v-power or momentum I drive the car much harder with the expectancy that it will not blow up.

 

[hydro s3]

Thanks tuffty for the good explanation as always.

 

[AGB-S3]

2/3 of the tank gone and its averaging 32 mpg , very similar to momentum .. inconclusive to say the least , but that is during the negative temperatures of this week's run to work and back ...may be slightly better mpg , next 45 ltrs back to T -mom

 

[AGB-S3]

final ,obb's gained a few mpg with new tank of momentum . harsher drive , spins more freely to the line . softer on the shell , gave the impression of more low down torque . less eager to spin .

 

[LJ_D]

Random comment but I always use Texaco in my A3 1.9 TDI.

Always did in my last car which was a Astra 1.7 DTi running 140-150bhp nearly double the standard 75bhp. I'd tried BP, shell regular and v-power, Esso, Tesco etc.... And found it ran best off Texaco, so with the Audi have carried on using Texaco.

Asda I'd rather run out, even when Astra was standard it'd cough and splutter off it. I was ready to run out when I put a fiver in it lol

 

[AGB-S3]

Texaco stations have moved out of the area , yes, used to be good , very few stations in easy reach these days , most are now blocks of flats , probably , tanks finally gave out , big job to dig up the forecourt ..

 

[LJ_D]

I must be lucky then, got a Texaco down the road from me.

Have yet to put there new supreme diesel in it haha

 

[hendo#1]

I have done a whole load of work in fuel storage depots, from Aberdeen to Southampton in the last 10 years, mainly for BP.

Dont get too hung up on different fuel 'manufacturers'. All fuel comes from the same 'stock'. A BP storage depot will have BP, Tesco, Asda, Sainsburys and Shell tanker lorries, all coming in and loading on the same gantries, from the same bulk tanks.

All the petrol stations in your area, regardless of who they are ran by, will be getting fuel from the same place.

The difference is in the additives. When they are loading they inject additives into the raw fuel. This is called a recipie.

BP and Shell spend millions researching and improving their recipies.

Supermarkets etc will only pay for a pretty basic recipe, hence their finished fuel quality not being as good.

BP and Shell will obviously keep their (much better quality) recipies to themselves. As you would expect, they spend millions £££ researching this.

The 'raw' fuel itself is the same for everyone usually. The additives are there to give a better, cleaner burning fuel.

 

[Gazwould]

Asda derv and JASO FB spec 2 Stroke oil is my recipe for the 1.9 PD .

 

[gone]

Now there's a can of worms, I used 2so in both Freelanders for the last 6 years.

 

[LJ_D]

Yeah I remember reading somewhere all fuel comes from same places and each manufacturer out there own additives in etc....

My results have been best with Texaco, it's down the road so may aswell stick with it haha

 

[hydro s3]

I use bp ultimate which i find is the best for me.

 

[Stuart B]

For me shell v power feels smooth, Tesco momentum feels dry and angry and bp ultimate is like having ready break instead of Porridge - although I can't even change gear at the moment so.. petrol shhmetral

 

[AGB-S3]

Guess that's as good a description as any , lol , seems to be all down to the burn-modifier / anti pinking potion ... I can remember , the bike with 10.25 :1 pistons , only liked 5 star
G,