Can anyone explain this - strange readings

[Davey C]

I wonder if anyone can explain this (it may be very simple, but currently i cannot fathom an explanation).

Without getting into a debate about what is the best fuel to use, i have been running on Tesco 99ron since i bought the car and consistently getting an average mpg of 28/29 mpg.

However, last month i was running low on fuel and the garage i stopped at didn't do any super unleaded so i filled up with normal.

Now i'm consistently returning readings of 32-34mpg.

How can this be? I thought the high octane stuff was suppose to increase your mpg?

 

[Middo]

i have exactly the same with my car. when i was using it for a boring motorway commute i swapped to 95 and got better mpg than with v-power. i couldnt figure it out either

 

[Mostro]

You're driving faster because you know you're running on poverty fuel?

Dunno, makes no sense. I reckon my mpg has been slightly better on BP Ultimate 97 than on regular, though remembering to turn the aircon off helped and the use of the car on two different tanks of fuel is never exactly the same.

 

[Se7en172]

Put it this way, I use 95 ron shell petrol, and I return 30mpg in the 197 cup(i don't hang around either) I hear alot of people who use V-Power getting as low as 25mpg up to 27mpg. I saw 27mpg once when Giving it a jolly good run over the mountain.

 

[Davey C]

You're driving faster because you know you're running on poverty fuel?

I would say that i probably do boot it a bit more because for some reason i think if i'm not spending as much then i can use more!

But....my mpg should be even lower in that case! not significantly higher! :S

 

[Davey C]

i swapped to 95 and got better mpg than with v-power. i couldnt figure it out either

I use 95 ron shell petrol, and I return 30mpg...V-Power getting as low as 25mpg

Well, atleast i'm not the only one. Thought my trip computer might have been buggered!

 

[mace¬]

Maybe its a bit like cheap wine?

Your car doesn't like drinking the cheap stuff

 

[Davey C]

Maybe its a bit like cheap wine?

Your car doesn't like drinking the cheap stuff

:cheers: It's just not thirsty anymore!

 

[DebV6]

My car doesn't seem to agree with v power. I've always used it since new, but since I've switched to BP Ultimate it runs soo much smoother, before it run terrible when cold.

 

[mardell100]

I fill the megane up with whatever is closest to hand, the magane does a steady 25-26 with my driving, and tend to use 95ron, even on expensive stuff the increase in *performance* is very minimal if not the same - but then driving around milton keynes is all about getting round the roundabouts faster haha

 

[Timmay]

ive only ever used sainsbuyrs super - might try other stuff and see what happens

 

[Davey C]

Its definately worth giving them all a bash to see what works best. Seems i might be saving a bit of cash from now on...

 

[Laura]

mines roughtly the same on each.

ph1 was better on 99 so ive alwys used that in the ph2, however i tried 95 this week and seems to be about the same,

although i tend to ignor my trip computer as its been saying 37.6 mpg lol

 

[ForceIndia]

It's because Tesco 99 is crap, part bio-fuel, nasty stuff. My 182 ran like a bag of nails when I used it, never again.

 

[Laura]

mine runs exactly the same what ever i give it

 

[TOGUSA]

i have always run my cars on the tesco 95 and always managed good mpg,
in the clio on the way down to Bath the other weekend i managed 42mpg i was in heaven........

even on the way back i managed 36mpg and i was gunning it to get home so im just happy with the tesco stuff