Did a search, and couldn't find mention of this...

I've noticed for quite a while (both with my first MY98 and current 01WRX)...

Car seems to have flattish / gruff response most of the time... But after filling up with fuel (usually BP std unleaded), drive off the forecourt, and vooooshhh!!!! Very noticeable jump in perceived performance and responsiveness immediately after the fill-up.

This lasts for a couple of days, then settles back to the usual state of wanting more 'zing'. - I usually go about a week between fill-ups.

What is going on? Am I imagining it (it seems very real to me)? Does fuel really have this type of '2 day freshness'? Is it oxygenation of the fuel during filling?

Does anyone else notice this effect?

Would really like to know how I can maintain the performance I get after filling up.

Cheers,
James

 

bttt... I really want to know why this happens and if any other Scoob owners experience this. Let me know even if you don't notice any such effect.

Thanks

 

Nothing for me. Shouldn't you be running your WRX on optimax though??

 

Mine is a UK bug-eye, and AFAIK should be OK on 95RON... I never really noticed any difference when running on optimax in the past, so just stick to cheaper 95 nowadays.

Next fill-up I'll try optimax again and see if I notice any difference this time...

 

I suppose the answer is to fill up every two days or so?

 

High octane fuels degrade after some time and could "loose" some of their octanes!

 

Hi James
I run mine on optimax, and have noticed if i don't use it for a week or two it goes a bit lumpy. Top it up and it runs fine

Red.