Petrol - MPG Thread

SoulUK

I have recently changed the petrol station i use to Sainsburys (as it has become very cheap) and have been plesantly supprised that my car seems to run better with it.

Whats everyones car, and which companys fuel do you believe runs best?

I'm currently useing Sainsbury fuel in a Hyundai Coupe.

I have used Tesco & Esso in the past, which dont seem to last as long

Ebe_Scrooge

Interesting thought. I've always held that all fuels are the same - i.e. they must meet a standard specification, it's just the additives that vary between supplier.

However, a couple of times recently I've filled up at Tesco, rather than my usual Esso, because I had 20 ppl off with their clubcard thingy - so when buying 55 litres or so it's a fair saving. I've noticed that my mpg dropped from around 53 to 48. This is diesel, by the way, but I guess the principle is the same. My driving style and actual routes over the week haven't changed - I do near enough exactly the same routes at the same time, week in week out.

I always thought the various additives just kept the engine clean, rather than affecting mpg, but now I'm not so sure .....

wiogs

I buy from the cheapest place I am passing. I have no regular route so can end up all over the country, but my mpg hasn't changed by any significant amount no matter what I put in.

torbrex

If I do a full tank fill-up (diesel), I get better mpg from Shell fuel than I do from Asda and I take the view that Shell fuel must be doing my engine less harm than the Asda stuff so the monetary savings at Asda does not make it worthwhile in the long term.

I did read a report somewhere that the water content in diesel varies quite a bit so obviously if the fuel you put in your tank has a high water content then you will get fewer mpg, I'm not sure how accurate that report was though.

SoulUK

From what i understand the fuels in the rawest form doesnt change much from seller to seller, its the additive packages each retailer adds to their own fuel.

fivetide

Ebe_Scrooge wrote: »

Interesting thought. I've always held that all fuels are the same - i.e. they must meet a standard specification, it's just the additives that vary between supplier.

However, a couple of times recently I've filled up at Tesco, rather than my usual Esso, because I had 20 ppl off with their clubcard thingy - so when buying 55 litres or so it's a fair saving. I've noticed that my mpg dropped from around 53 to 48. This is diesel, by the way, but I guess the principle is the same. My driving style and actual routes over the week haven't changed - I do near enough exactly the same routes at the same time, week in week out.

I always thought the various additives just kept the engine clean, rather than affecting mpg, but now I'm not so sure .....

Out local Esso is filled up by Greenergy tankers - the same people who supply.... Tesco!

TonyMMM

I use Tesco (most often) but also regularly use Esso and Shell and occasionally BP - never noticed any real change in MPG between them.

bod1467

I live (and work) in the Central Belt of Scotland. Not too far from me is the Grangemouth refinery (and tank storage facility), and it is said that this facility serves pretty much all of Scotland.

I sometimes do work there too, and I have seen road tankers with various different company logos all lining up to be filled from the same storage tanks. (Whether these then go elsewhere for post-processing I can't say).

FiremanDave

fivetide wrote: »

Out local Esso is filled up by Greenergy tankers - the same people who supply.... Tesco!

Do esso have some alliance with tesco?

Our local esso has been closed and is now a tesco mini market with a petrol forecourt.

spikyone

Ebe_Scrooge wrote: »

I always thought the various additives just kept the engine clean, rather than affecting mpg, but now I'm not so sure .....

You've said you drive a diesel. Modern diesel fuel injection systems (and increasingly, petrol injection systems) are incredibly intricate and complex systems - the holes in the fuel injector nozzle will be about the diameter of a hair and use a delicate pressure balance to open and close. The holes direct fuel into the cylinder in a way that ensures the most efficient and complete combustion of the fuel; they will be specifically orientated relative to the inlet and exhaust valves. The high pressure fuel pump will also contain one to three small valves that control the pressure of the fuel being delivered to the fuel rail. Imagine what happens to the engine efficiency if the injector holes or fuel pump valves get gunked-up...


@fivetide and others - the company that delivers the fuel has no bearing on the composition of the fuel.

Ebe_Scrooge

spikyone wrote: »

You've said you drive a diesel. Modern diesel fuel injection systems (and increasingly, petrol injection systems) are incredibly intricate and complex systems - the holes in the fuel injector nozzle will be about the diameter of a hair and use a delicate pressure balance to open and close. The holes direct fuel into the cylinder in a way that ensures the most efficient and complete combustion of the fuel; they will be specifically orientated relative to the inlet and exhaust valves. The high pressure fuel pump will also contain one to three small valves that control the pressure of the fuel being delivered to the fuel rail. Imagine what happens to the engine efficiency if the injector holes or fuel pump valves get gunked-up...


@fivetide and others - the company that delivers the fuel has no bearing on the composition of the fuel.

When you put it like that, it makes a lot of sense !

Regarding the different companies - it's been discussed on this forum many times and at great length in the past. I think the general consensus is that yes, Tesco, Asda, Esso, Shell etc. all fill their tankers from the same source. But they then add different "secret ingredients", and this is what can make a difference. As per my earlier point, I was never sure whether this changed the MPG or just kept the engine cleaner, but the post from Spikyone does seem to sound logical.