Daz1121

I'm doing a run at the weekend from Wirral to NEC and back to will do fuel check on that journey. get about 23mpg around town and a mix of town and dual carrage way driving have got 26mpg and that was booting it a bit.

pslewis

I don't understand those who say, "You Have a Fast Car, You MUST Drive it Like a Chav!!"

There is NO need whatsoever to drive like a **** just because you have a fast car .... I treat my car with the utmost respect, warmed thoroughly before any engine speed over 2500RPM then accelerated gently unless I want a 'little play'

I take it to the redline now and again - maybe once a month ..... never hit the rev limiter yet though!!

I enjoy my car too much to abuse it .... just because its fast!!

Pete

Carl2

Pete you're not alone, one of the guys on one of the Gtir forums reported going down to 14mpg on Tescos 99ron. He wasn't impressed.

pslewis

Indeed!!

I fully expected to be proudly posting here that I had broken through the 40+ barrier!!

Never thought I would be posting that its like having a hole in the tank!!

Pete

dpb

Folks .!..check your individual post counts an then check Petes - its fun for Pete. ....perhaps- but hes playing you for suckers

hoskib

iTrader: (1)

don't need to worry about what level you fill up to, just zero your trip when you put petrol in, then next time put in X amount, get a receipt.

then multiply the litres put in by 0.22, then divide the number of miles done on your trip into this figure and hey presto. an absloute *** on figure not just 'around 20mpg'

pslewis

Yep, thats just what I said!!

Pete

pslewis

Then check on this pratts post count and ask yourself why he hates me so .... could it be because he can never catch me???

Pete

hoskib

iTrader: (1)

did you? oops

just sort of skated through the waffle and the mpg question caught my eye

wouldn't risk running it to the light if i were you. given your current **** poor mpg that is

bluto22b

Maybe that is because you have NEVER driven above 40 mph. Mr Pissy Lewis is one of the 40mph EVERWHERE brigade.

dpb

Pete, if i believed for one second you got 38 mpg driving normally id sling you 5 grand for it .........as its total bollox i wont..

Nick Read

Chachi - yes octane IS to do with the stability of the mix under compression, but the Impreza engine isn't particularly low or high compression for a turbo engine. The easiest way to understand high octane fuel without getting too technical is to think of it as burning SLOWER than normal fuel. It takes more pressure and heat in the cylinders to get it to pre-ignite - i.e. to start burning before the spark plug fires - than normal fuel does.

This allows a number of benefits for a high output turbocharged engine: 1. Higher compression is possible = more power 2. More ignition advance is possible = more power 3. Higher engine temperatures are tolerable = more operating safety 4. More boost is possible = more power

So with all things being equal, high octane fuel is best for a high output engine like a Scoob's. Unfortunately all things are NOT equal because super unleaded costs more. Bummer. And when the engine's been designed for super, running it on normal UL reverses all those beneficial effects mentioned above - i.e. the ignition timing will be retarded, boost will have to be cut and above average temps and conditions cannot be tolerated. Bad news all round.

So to turn to the original point of the thread, I'd find it hard to believe that a certified British pump fuel, whatever the brand, would cause a halving of mpg and I think it more likely that it's just a coincidence that everyone's switched from Optimax to Tesco 99 just as we hit winter. Ask any AA or RAC patrolman and the vast majority of their calls over the winter are caused by flat or dying batteries. ANY function that needs electrical power on a car is sapping mpg, simple as that. I can think of times during the last couple of weeks when I've had the air con on full blast, rear demister on, stereo on, sidelights, headlights and front and rear foglights on, and both front and rear wipers. The cold starts need a lot more electrical energy from the battery so even before you've started moving you're at a disadvantage, your engine is playing catch up to keep the battery charged. The cold engine - that stays cold for longer if you're being sympathetic and not thrashing it from the word go - uses more fuel on 'choke' while it's out of its proper operating temp range.

I'd say that I've seen a drop of at least 5mpg over the last fortnight, and I've been using Tesco 99 for the last couple of months. Prior to the cold weather I was getting 26mpg on Tesco 99, and prior to that around 24-25mpg on Optimax. Now I see around 20mpg.

This may be the explanation for your loss of mpg anyway. But there's an easy test to do. Run the tank dry, stick in a tankfull of Optimax and see how it comes out. Then try another tank of Tesco and see if it goes back to low mpg. It's in no-one's interest for us all to pay more than we need to for super unleaded, and I'm pretty happy with my Tesco 99 that's been 85-90p a litre each time I've filled up.

alexf2003

I get 26-28mpg driving gently in my 1996 STi RA.

on tesco 99

Alex

dpb

Good god another lewis convert.....

highlander68k

I'd take that as a compliment Nick

Does everybody know that many of the petrols have different mixes for the 4 seasons (or two minimum)?

In the winter there should be a high volatility fuel in the pump, whereas during the summer it will be much lower.

There may be a period where a garage with a low fuel turnover still has the old fuel in their tanks i.e. The Autumn-Winter season. A sudden cold spell can result in you putting in fuel that isn't optimum for the conditions. This also applies to those weekenders who make a tank of petrol last for 3 months!

Reports I have access to show that up to 50% higher fuel consumption is possible during the winter months. If that's the case, then the figures being quoted here are a mere drop in the ocean.

MaDaSS

pslewis, this just shows what a muppet you are! Who the **** would buy a ****ing Scooby and worry about mpg? You obviously drive like a grandma and one can only suggest you go buy a ****ing diesel if want more mpg.
Any **** that puts supermarket fuel into a scooby wants ****ing imo.

Nick Read

LOL yeah the dreaded 'supermarket' fuel that they go out of their way to refine to a sub-standard quality, (which somehow still passes the standard tests and checks to allow it to be sold in the UK) in special multi-million pound 'supermarket' refineries that none of the petrol companies use...

Wake up! Supermarkets don't even make hardly any profit on fuel, in fact some would say that they actually make a loss. Selling fuel cheap is simply a way to encourage you to shop at the supermarket and put other petrol firms and supermarkets out of business. They've no interest in bull****ting the public about their fuel; you can take it or leave it. Unlike the big petrol companies, who are constantly claiming their stuff is better than anyone else's, playing on people's paranoia, and keeping you paying more for it than you should. But that's your choice. Round my way, I've been paying 5-10 p less per litre for Tesco 99 rather than Optimax 98 and I don't have to go out of my way to a Shell station to get it. The fuel economy and performance of the engine are the same or better, and I'm paying less money. I'd have to be pretty thick or some kind of rich masochist not to.

Houghton

iTrader: (1)

**** ** ******* * **** *** ********* ****, ****'*!!! *** *** ****** *** ****** *****. *****'* ****** ** ***** ******* ***** 99***

MaDaSS

LOL.
Dont you just love forums?
And if you think i am gonna belive a supermarket makes no money on fuel, then you really are off your little trolley!

ru'

I don't know the details however it wouldn't suprise me if this was in fact the case. Supermarkets can afford to make very low margins on some items if it means they get more business elsewhere. It's a common marketing tactic - hopefully you don't think that a supermarket makes a fixed X% profit on everything it sells?

pslewis

Well, I've now gone back to my old faithful Sainsburys Super at 87p .... will do me fine

Calculated that the Tesco 99 was returning me 19mpg That is NOT acceptable for me ............ I fully expect to be back up where I should be, at 35mpg!

Pete

pslewis

You wouldn't get my car for 10 grand!!

5 grand would simply get you a 'sit-in-it'!

Pete

Houghton

iTrader: (1)

You will report back on consumption with Sains. Super so we get a comparison?
BTW how often do you fill up? That Tesco's tankful wasn't from July/August was it? Just interested to know after what highlander 68k posted.

dpb

10K......dream on.

pslewis

That TESCO petrol was from the last week in October (2005!!!)

Pete

pslewis

It must be YOU who does the dreamin' ................... as I said, YOU ain't having it FULL STOP!

Pete

ru'

Why did you swap from Sainsbury's 97 RON to Tesco 99 RON? You obviously don't care about the Ron levels or performance etc.


Also, as an 'engineer' do you have any ideas why you got such a bad suposed mpg figure? Or could it be your calculator (abacus?) or something?

I too would be interested to hear what your figures are now you're back on the Sainsbury's stuff, after your long and extensive trial of Tesco's.

Daz1121

I've just done a run from Wirral to NEC Birmingham and back again this weekend. Car is a Classic 2000 Turbo with Magnex system 1st cat back. Done a steady 3000-3500rpm in 5th gear on the motorways and it was a 250mile round trip of which 230miles was all on motorways. Using Shell Optimax average fuel consumption was 28mpg which I thought was fairly good. Might try same run next time with Tesco's 99RON and see how the figures compare.

highlander68k

Make a note of today's temperature too

NXG

If you're leaving it this late to refuel, your low mpg if more likely due to having sucked sludge from the bottom of your tank....

Don't know which model you have, but I've been advised that standard UL is too low a RON to run my MY03 WRX on. My wife's MY00 has seen a big improvement in MPG and running response since switching to a 100% diet of Optimax/Ultimate (whichever is available) about 18 months ago.

Her pedestrian driving style back then also contributed to soo many errors building up in the ECU log it went into 'limp home' mode. She now boots it on a regular basis and it hasn't had a problem since. It's actually running better now than it ever has.

Finally (you'll be glad to read), surely MPG worries are for people with 'normal' cars, not enthusiats with performance saloons????