my personal view is quiet different, tesco 99 doesnt compare at all to optimax.
my car runs and idles very roughly for a good few mins/miles when i fill up with tesco 99.
but not if i switch back to optimax, or indeed sainburys 97!


in fact if i get stuck for no optimax ill go to sainburys 97 as this is considerable cheaper than tesco (at least where i am).



At the last herts meet this was discussed for a bit and while the majority didnt like tesco 99 we had mixed results, so it may come down to individual cars / maps...
 
Personally I don't think its that great! I've used two tanks of 99 RON now and unless I got a dodgy batch it didn't feel any better then 95 RON. BP's ultimate or Optimax seems to burn the best in my car.
 
I've got a belly full of Tesco's "99"(!) ron in the Leon and to be honest I can't tell sweet FA difference yet. Whether this is because it needs time to adapt or not I don't know. I've only ever used Optimax from new and was just fascinated to give it a try.

I do believe different fuels may have different burn characteristics but find it hard to believe that road cars can deliver night and day differences between fuels. If your getting that much difference check your plugs and leads.
 
i have heard tesco 99 is good but u need to do one 99tesco fill up then one 98optimax fill up and so due to the mixing in the tesco 99 is not very clean aqnd 98 optimax is good for cleaning the car out
 
Filled up at tesco's in Northampton tonight, and noticed they have now got 99RON petrol ..

99.9p ...
 
mrcoyote said:
Surely if they're selling it as 99 octane and it's in reality 98, then they're breaking the Trade Descriptions act?
look up or find out the RON and the MON figure

with both of those for both fuels you can find out which is technically the best fuel

im off tomorrow to try and find out
 
Turbowayne said:
Any of this Tesco 99 octane stuff in the Swansea area YET ???
Optimax is a bit hefty at just over a £1 a litre !!!

:cry: :cry: :cry:

Fabian Way Shell is well cheap. Last time i seen it it was 96.9.
 
Peterborough Tescos have the 99RON fuel in. I tell ya, if Ben Johnson p!ssed in the tank the car could not go any faster!

I usually use 95RON and now and again get a couple of tanks of super. So I thought I'd try the tesco 99RON (this week @ 93.9p/l) and waited a 100 miles or so. Now going full throttle in 2nd/3rd will try to light the tyres up where it wouldn't before (yes, it was dry tarmac!), even on 98RON Optimax. I do notice more exhaust noise too like a couple of others do, sounding a heck of a lot more agressive, not necessarily louder. For that reason, I think I'll revert back to 95RON as I believe something's going to let go with the extra torque! Better be safe than sorry.

Gets the thumbs up by me, but remember extra power means extra where and tear. I'm into longevity. :D
 
I decided to give Tesco 99 a go this week. Filled up and immediately noticed a difference - MPG has dropped around 2-3mpg and it's a bit rough for the first minute or so in the morning.

From this experience, I don't think it's worth it (especially when it's only 1p less than Optimax around here). Does the ECU take time to adapt even if the car has been run on nothing but Optimax for the last few months?
 
tesco 99 ron / 87 mon = 93

optimax 98 ron / 86 mon = 92

on paper its tesco all day long - on a dyno with an engine with enough power to actually show up minor differences its been shown optimax actually runs a lot better power wise

horses for course i suppose