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Lone_Bullet

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What are everyone's thoughts on supermarket fuel? I'm talking petrol if that makes a difference. I've always used Shell or Esso but now I can get supermarket fuel for under a £1, I'm tempted.

 

I gather it's all the same fuel, just with difference additives. Is there really much of a difference?

Here it doesn't matter, I do notice that cheap fuel tends to burn quicker. Like it's using more gas for some reason, amount of milage never changed from fill up to fill up.

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What are everyone's thoughts on supermarket fuel?  I'm talking petrol if that makes a difference.  I've always used Shell or Esso but now I can get supermarket fuel for under a £1, I'm tempted.

 

I gather it's all the same fuel, just with difference additives.  Is there really much of a difference?

 

I generally cycle between tesco, BP or shell, as those are the petrol stations I drive past on the way to/from work.

 

I've noticed no real difference between any of the 'normal' fuels.

 

on a 2008 vintage car, i'd happily run it all day long on supermarket stuff, maybe change one tank out of ten to V power or something similar and give it a good old italian tune up, especially if you normally drive short (under 10 mile) distances)

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Cool.   Thanks.  I do treat it to a bit of V Power every now and again so hopefully should be OK.  Shell are being very slow to reduce their prices near me.  Still around 114.7 or so which is pretty cheeky I reckon.

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I know a chap who does all sorts of buggering about with cars, tuning and such, as a business, and he tells everyone not to touch supermarket fuel as it's cheap for a reason. Basically the dregs and rubbish and doesn't burn clean.

 

I've no way to verify this though.

 

On the other end of the scale, another friend runs his (diesel) on nothing but premium fuel. He's done the sums and gets better economy, even though costing more initially.

 

I buy BP for nectar points!

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if you've got a car that you've mapped for higher octane fuel, then yeah, supermarket stuff will make it run like a bag o'spanners, however I'd estimate a good 95% of the cars on the road AREN'T mapped for high octane fuel.

 

It's likely probable that supermarket fuel is a marginally 'lower' quality, however thanks to standards etc it'll still perform like it should.

 

'proper' petrol might perform slightly better, though.

 

Only one way to find out, however ;)

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Hey guys!

 

Just got my Yaris Mk1 serviced/MOT'd for quite a bit. Included getting a clockspring replaced for the airbag, to clear a faulty sensor.

 

However it came back after a few days of driving - A little googling and a quick visit to Toyota's website says that I need to take it in for a voluntary recall, due to the chance the airbag will just spontaneously deploy (!)

 

Getting it booked in ASAP, but I was just wondering if you guys think I can get it back to the MOT place for a refund, or if they've missed anything else.

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You could just leave it.  It would make even the most boring of journeys interesting with it in the back of your mind 'will my face be blown off today?'

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Don't ask, you don't get.

 

On the other hand, if it's not an approved toyboata dealership/repairer they wouldn't know about the recall, so be prepared to accept a reduced price MoT and service for next year, as they won't be able to send the (now used) part back to supplier and will have gotten rid of your existing one the day after they changed it.

 

Better to chase toyota for some good will, to be honest. phone up customer service and kick up a fuss.

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Not enough money.

 

For now.

 

Mwah-ha-ha.

 

<cough>

 

I have to remortgage soon.  I also care this much about them being LHD:

 

 

 

Might me tough to spot there, because it is nothing.

LHD is fine, HGV is fine. Top speed of 55mph might be a bit of a problem...

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Lhd = left hand drive. Steering wheel on the wrong side.

 

Hgv = heavy goods vehicle. Special license due to maximum gross weight, size etc

 

:)

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All the above is correct.

 

So, it is theoretical but with the standard 3.14:1 diff ratio, 2.07:1 hub ratio and a 1:1 gearbox ratio in top gear with a wheel size of 365x80R20 and a redline of 2800 from the 5.7l Merc straight six diesel you should get 55.

 

You can swap in a set of 23:9 diffs and get a theoretical 68mph.

 

Sounds legit.

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Fair enough. I know a couple of people who have had them and had nowhere near 55mph.

 

Also, I wouldn't fancy swapping an axle on a unimog. 'Spose you do heavy plant though and have access to the kit required, but for me at home, by the side of the road (it would only fit on the drive with the application of speed...) not a chance!

 

Oh, to have enough money to be able to spend the day faffing with vehicles...

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All the above is correct.

 

So, it is theoretical but with the standard 3.14:1 diff ratio, 2.07:1 hub ratio and a 1:1 gearbox ratio in top gear with a wheel size of 365x80R20 and a redline of 2800 from the 5.7l Merc straight six diesel you should get 55.

 

You can swap in a set of 23:9 diffs and get a theoretical 68mph.

 

Sounds legit.

I'm going to be that person. That's tyre size you quoted, not wheel size.

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I'm going to be that person. That's tyre size you quoted, not wheel size.

 

You win one internet.

 

 

Yes, my trolley jack is a ten tonne one and our ramps are thirty tonnes.

 

Even those wheels are light compared to the ones on the plant which are about 350kg.

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Well, I took a punt on some supermarket fuel.  I think my car is thinking wtf is this stuff?  Normally after fill up, ignition on, boom, 400+ miles on the trip computer.  With supermarket fuel, range stayed the same but increased in 1 mile increments as I was driving.  Most odd.

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The tank range is calculated by an algorithm that knows how much fuel you have and how much you are using.

 

However to stop it from spitting out a load on nonsense every time you speed up or slow down the algorithm will use a weighted average of your fuel consumption over the last n minutes.

The value of n and the nature of the weighting will vary from manufacturer to manufacturer.

 

What is probably happening is that as time goes by the different fuel consumption of the new fuel is gradually replacing the old data in the average fuel consumption part of the algorithm.

At the same time the fuel might have resisted mixing in the tank and the ratio of new fuel to old may be changing as the fuel is depleted.

 

The negative effects (bonkers tank range readout) of those factors will ameliorate over time.

 

Temporary problem.

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Now that makes sense.  I'd never have thought a slightly different fuel mix would have that much impact.  I did have a look at the real time MPG for a bit but it didn't seem to vary wildly from using the regular fuel.  Then again the car's computer is probably more accurate than my briefly observed data.

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The instant mpg isn't instant either, it is also a weighted average, it is just averaged over a shorter time.

 

Also, the fuel use isn't particularly accurate.

It knows the injector flow rate and duty cycle but both of those are manufacturer rated and can wander with age.

The mpg doesn't actually matter to the ecu at all, it is looking at the information from the lambda sensor and adding or subtracting fuel to maintain the pre-set stoichiometric ratio for a given set of conditions.

 

There is not legislation requiring those readings to be accurate and the car doesn't need that information to work properly so it can be a load of *badger*s.

 

An interesting experiment is to record the mileage (also not that accurate) and quantity of fuel required to fill up at each fill and do a quick mpg calc from the known (legislated) dispensed volume.

Compare that to your trip computer to see how close it is.

Better yet if you have an idea of how far out your odometer is which you can find out by comparing indicated speed to GPS speed to time needed to cover a known distance (100m between motorway markers should take 3.2s at 70mph or 32s for 10 of them).

 

Anyway, I did all that with my Skoda vRS and the fuel consumption indicator was out by 14%

 

 

 

Check this out.

The tyres on the Skoda were 215x45R17 which are 625mm in diameter.

615mm measured with the correct tyre pressure and 590mm with a bit of a flat.

 

An effective circumference of 1.93m when full and 1.85 a bit flat

4% might not sound a lot but that is your care going 4% less far than you thought at 4% slower than you thought.

That will totally ruin a set of fuel consumption calcs.

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