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MPG and how to improve yours.


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Warning long post. :blush

 

Ok, some background first.

 

I buy cars new and keep them long term to help with running costs.

The car that my Skoda Fabia TSI 90 replaced was a Diesel, 13 years old and had done 131 K miles.

 

The depreciation per month worked out at less than £60.00 per month. This is good.

What I bought it for minus what I sold it for divided by the number of months I had it.

It was costing me more in fuel per month than this, and it was doing 60 MPG.

 

I would not buy a Euro 5/6 Diesel for long term ownership. So swapping to a petrol was a slight concern for me.

I was hoping for 50 MPG and with petrol now, just, cheaper than diesel to slightly offset the lower MPG.

In the UK diesel was, for years, cheaper than petrol but now it is the other way round.

 

The Skoda Fabia I bought in June 2016 was returning 50+ MPG for the first 8 months, including the winter.

Now the car is run in and the warmer weather is here it's now above 60 MPG long term for the last 4 months.

It has also had it's first service at 10 months and I don't know if this has helped.

Very impressed with this engine and it's performance/economy balance.

This is also helped by where I live. North Dorset UK is in the sticks/country with very little town driving.

 

Now back to the title and how do I achieve this. :)

There is no one magic trick but all of these, in no particular order, help:-

 

Don't do short journeys when the engine is cold. The TSI engine warms up quickly though.

If you have several places to go, try going to the furthest one away first and work your way back home.

 

The higher the tyre pressures the lower the rolling resistance so check your pressure regularly.

In the UK the highway code states once a week. :o

Try the higher pressure settings for your car found inside the fuel filler cap.

 

Make sure the brakes are not binding/rubbing.

I remove and clean/re grease all the brake pads once a year in the Autumn.

Mine needed doing the first year after 5 months ownership. This also helps them to last.

The last car at 13 years/131 K miles had used 2 sets of front pads, 1 set of front disks and 1 set of rear pads only.

You also want to use the brakes firmly, occasionally, to keep them working. A bit like your own muscles.

 

 

The best state for the car to be in for fuel economy is:-

In gear with the engine above 1500 rpm but with your foot off the throttle.

So try easing off the throttle well before you need to brake as braking is wasting energy you have already used.

 

If you have done the above points then you will find the car will hardly slow in this state.

Without holding other people up, try taking your foot off the throttle approaching a slower speed limit with the aim to reach

the new slower speed at the speed sign without braking. You will find it is a long way.

If the engine speed gets lower than 1400 rpm then the car starts to supply the engine with fuel. Can you change down at this point?

You can check this, using the instant fuel consumption read out on the MFD. Multi function Display.

 

When accelerating after a corner/roundabout try this method:-

Instead of accelerating in each gear for several seconds I will:-

From say 20 to 50 mph accelerate in second for several seconds and then block shift up to fifth.

From say 30 to 70 mph accelerate in third for several seconds and then block shift up to fifth.

 

You are accelerating for less time and reaching your cruising speed quicker.

Both are good for fuel economy and has the further benefit of using the engines higher revs which helps to keep your engine healthy. 

The engine is also very good/sweet at higher revs. Well that's my excuse anyway.

 

I switch off the stop/start every time I start the engine but will use it if I know I will be stopped for a while.

 

I run the tank until the fuel warning light is on then fill it right up.

It will go for 100 miles before the fuel gauge comes off full.

The most I have put in is 43 Litres so I think you can go past the '0 miles to go until you need to fill up' warning.

 

There is more I do but lets start with this.

 

Thanks for reading this.  AG Falco.

 

 

 

 

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Good summation AG Falco.

That all pretty much ties in with how I drive especially the use of 2nd and block shifting.

I have some additional thoughts I need a bit of time to put together and some material that others might find interesting/useful.

So to be continued....

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This document from VW with economy tips related to a Golf 1.4tsi is quite simply the best I have come across in terms of simply explaining all the most relevant aspects of economical driving, performance of the 1.4tsi engine (same family as the 1.2tsi in the Fabia) and the current official Euro economy tests.

I've forgotten the name of the original Briskoda member who put it up (forever thankful to him though) but I think all manufacturers should present this level of detail with every vehicle they manufacture.

For what it is worth I find the graph showing the gear/road speed/consumption for the manual Golf 1.4tsi (90kw) near identical to what I achieve with my manual Octavia mk3 estate1.4tsi (110kw) up to our 110kph speed limit.

spritspartipps_par_0008_file.pdf

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16 hours ago, AGFalco said:

Warning long post. :blush

 

Ok, some background first.

 

I buy cars new and keep them long term to help with running costs.

The car that my Skoda Fabia TSI 90 replaced was a Diesel, 13 years old and had done 131 K miles.

 

The depreciation per month worked out at less than £60.00 per month. This is good.

What I bought it for minus what I sold it for divided by the number of months I had it.

It was costing me more in fuel per month than this, and it was doing 60 MPG.

 

I would not buy a Euro 5/6 Diesel for long term ownership. So swapping to a petrol was a slight concern for me.

I was hoping for 50 MPG and with petrol now, just, cheaper than diesel to slightly offset the lower MPG.

In the UK diesel was, for years, cheaper than petrol but now it is the other way round.

 

The Skoda Fabia I bought in June 2016 was returning 50+ MPG for the first 8 months, including the winter.

Now the car is run in and the warmer weather is here it's now above 60 MPG long term for the last 4 months.

It has also had it's first service at 10 months and I don't know if this has helped.

Very impressed with this engine and it's performance/economy balance.

This is also helped by where I live. North Dorset UK is in the sticks/country with very little town driving.

 

Now back to the title and how do I achieve this. :)

There is no one magic trick but all of these, in no particular order, help:-

 

Don't do short journeys when the engine is cold. The TSI engine warms up quickly though.

If you have several places to go, try going to the furthest one away first and work your way back home.

 

The higher the tyre pressures the lower the rolling resistance so check your pressure regularly.

In the UK the highway code states once a week. :o

Try the higher pressure settings for your car found inside the fuel filler cap.

 

Make sure the brakes are not binding/rubbing.

I remove and clean/re grease all the brake pads once a year in the Autumn.

Mine needed doing the first year after 5 months ownership. This also helps them to last.

The last car at 13 years/131 K miles had used 2 sets of front pads, 1 set of front disks and 1 set of rear pads only.

You also want to use the brakes firmly, occasionally, to keep them working. A bit like your own muscles.

 

 

The best state for the car to be in for fuel economy is:-

In gear with the engine above 1500 rpm but with your foot off the throttle.

So try easing off the throttle well before you need to brake as braking is wasting energy you have already used.

 

If you have done the above points then you will find the car will hardly slow in this state.

Without holding other people up, try taking your foot off the throttle approaching a slower speed limit with the aim to reach

the new slower speed at the speed sign without braking. You will find it is a long way.

If the engine speed gets lower than 1400 rpm then the car starts to supply the engine with fuel. Can you change down at this point?

You can check this, using the instant fuel consumption read out on the MFD. Multi function Display.

 

When accelerating after a corner/roundabout try this method:-

Instead of accelerating in each gear for several seconds I will:-

From say 20 to 50 mph accelerate in second for several seconds and then block shift up to fifth.

From say 30 to 70 mph accelerate in third for several seconds and then block shift up to fifth.

 

You are accelerating for less time and reaching your cruising speed quicker.

Both are good for fuel economy and has the further benefit of using the engines higher revs which helps to keep your engine healthy. 

The engine is also very good/sweet at higher revs. Well that's my excuse anyway.

 

I switch off the stop/start every time I start the engine but will use it if I know I will be stopped for a while.

 

I run the tank until the fuel warning light is on then fill it right up.

It will go for 100 miles before the fuel gauge comes off full.

The most I have put in is 43 Litres so I think you can go past the '0 miles to go until you need to fill up' warning.

 

There is more I do but lets start with this.

 

Thanks for reading this.  AG Falco.

 

 

 

 

Are you going off your own calculations for the MPG, or the car's trip computer? How many miles do you tend to get from a full tank of fuel?

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Small Family City Cars and good to just get in and drive when you need to get from one place to another if a car is needed.

If you can go short distances without a car then walking or cycling might be a good idea.

 

A gallon of fuel is now costing well below the Minimum Wage for an adult worker (£7.50 an hour.)

A Tank of fuel for a car to cover the likes of 450-500 miles is not taking a full days wages of the lowest paid workers thankfully.

(It might still  take a full days income after tax and NI though. Or 1/2 a weeks Government Pension!

 

If you can save on buying 4.546 litres of fuel by economic use and driving then that is an extra £5.20 or so in the hipper to spend on something else which is nice.

 

EDIT, 

PS.

Referring to below, if you live maybe up the top half of the UK were daytime and night time temps can vary lots then keeping the tank of fuel full between October and March / April when Winter Grade Fuel is at Filling Stations is maybe a good idea because full of fuel leaves less space in the fuel tank walls for condensation / H2o / Moisture that tanks can get, just like Filling Station tanks do, or used to do.

 

 

Edited by Awayoffski
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I never run the tank down so the fuel warning light comes on and only ever brim the tank full if doing a long journey,can't see the point in lugging all that extra fuel (weight) for my normal everyday motoring,depends on your weekly mileage I suppose.

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4 hours ago, sandman said:

I never run the tank down so the fuel warning light comes on and only ever brim the tank full if doing a long journey,can't see the point in lugging all that extra fuel (weight) for my normal everyday motoring,depends on your weekly mileage I suppose.

Basically I agree with you, although in a Fabia the difference between full and half full is about 20kg weight and in a Yeti 30kg? Not sure the difference in consumption will be really noticeable as I have had my Octavia fully loaded on a longer trip and it only seemed to affect the returns by a couple of mpg, despite near full load.

Where I am in Adelaide Australia our fuel prices go through a roughly 3 week cycle where the fuel price can vary by nearly 30%. 

Naturally I always try to fill at the lowest price point but it is a bit like playing 'Russian Roulette' where the price keeps dropping to an indeterminate low point and then all stations bounce back up to the highest price point to begin the slow drop down again. Means I fill more often than I probably need to but it is more economical in cost if not returns to do it that way.

I'm sure that UK petrol stations don't have that sort of price variability but I'll find out soon enough when we visit in September. I'm also sure that your petrol prices will ensure I rent something (really) economical and I'll be doing my best to maximise returns :) 

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5 hours ago, Octy09 said:

Are you going off your own calculations for the MPG, or the car's trip computer? How many miles do you tend to get from a full tank of fuel?

 

- I kept detailed brim to brim figures for the first 12,000 miles, and also the corresponding Trip Computer figures.   Over that mileage, the average difference between both, was 0.1mpg. So I gave up the paper figures and just trusted the car's figures!  ( For anyone interested, the figures varied between a 1.07mpg underread to a 0.55mpg overread )

 

- Looks like an average of about. 360-370 miles to a tank. That range looks like it's increasing lately. There's over 25000 miles on the clock now. The MFD long-term figure is showing 43mpg today. Incidentally, I haven't tracked the "Range" figure, but it seems to look a bit optimistic, but I haven't done the numbers on it.

 

4 hours ago, sandman said:

I never run the tank down so the fuel warning light comes on and only ever brim the tank full if doing a long journey,can't see the point in lugging all that extra fuel (weight) for my normal everyday motoring,depends on your weekly mileage I suppose.

 

- Part of this, for me, came originally from the practice I heard in relation to diesels, and it's to do with reducing (at least a little) the condensation in the tank (as Awayoffski mentioned) and therefore water in the fuel/injection system ...

... but mainly, I do it because it saves time!  I hate wasting that time (and fuel !) driving off-route to get a filling station.

In balancing the cost of time with the cost of carrying the fuel around, I value the time more. It's whatever suits each of us, isn't it ?!

 

 

Edited by Dithane
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6 hours ago, sandman said:

I never run the tank down so the fuel warning light comes on and only ever brim the tank full if doing a long journey,can't see the point in lugging all that extra fuel (weight) for my normal everyday motoring,depends on your weekly mileage I suppose.

This was based on my mileage (low) hence my comment "depends on your weekly mileage" .With regards to brimming the tank to reducing condensation I used to do this when storing my  motorbike during winter, didn't think it would apply to a vehicle in regular use,but who knows?  

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It totally applies still dependent on location / climate and ambient temps,  ie, parts of the UK from Autumn to Spring and the month inbetween, July usually.

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Hi all,

 

I do brim to brim calculations for the MPG and have also compared this to the car's figures.

The car's figures were optimistic until the first service and are now pessimistic? :speechless:

 

Most of my mileage is to work and back, but I don't go past a fuel station.

So a fill up happens when I go shopping, about 7 miles from home.

 

The fuel warning light comes on near the 500 mile mark.

So 500 plus miles per tank is the normal at this time of year.

 

The last tank did 572 miles with 5 miles to fill up showing on the car.

Once the fuel warning light comes on, the miles until you need to fill up goes down quicker than the miles actually done!

 

During the last winter it was doing low to mid 50's.

The MFD long term fuel consumption is showing just above 60 MPG at the minute.

 

One bone of contention for me is that both of the cars I run only have a 5 speed gearbox.

But both car engines are available with a 6 speed gearbox in other forms.

 

Gerrycan:  thanks for the link, looks good but still reading it though.

I once went swimming in a pool on the top floor of a Hotel in Adelaide.

I think it is now called the Rydges South Park on South Terrace.

 

Thanks AG Falco

 

 

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Hi Awayoffski,

 

It was 43 Litres but I fill up to the brim and can do 100 miles before the fuel gauge moves off full.

 

Thanks AG Falco.

 

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I use Fuelly to monitor my true consumption (in my signature if viewed with a real PC) but I'd also recommend checking odometer and speedometer accuracy against a GPS. The odometer on my Octavia is very slightly 'pessimistic' (shows less than I have travelled) by less than 1%. the speedo is about 6 or 7% optimistic depending on speed (shows higher speed than actual).

The average consumption displayed since refuel when new was pretty spot on actual, maybe slightly pessimistic (showed worse than actual) but after near 38k km this display has gone to slightly optimistic especially on good real economy runs, but only by a couple of mpg. Good enough for my purposes anyway.

The maxidot digital speed display reflects the speedo inaccuracy but the Average speed display is calculated from the odometer and is therefore very accurate.

If I need to press on a bit then I use true (GPS) speeds and if I'm in less of a rush and want better economy then I drive to the speedo display and get something like 5 mpg better returns.

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If brimming when there is a 5 mile range and 'only getting in 43 litres' there must be plenty fuel left in the tank considering the tank capacity and up the pipe when brimming.

 

I would be tempted to brim and then maybe drive 55 miles with a can of petrol with 4.564 litres in and then see if you can pour all that in and brim again, 

or if it easily takes the gallon and has space for more.

That has been my way of checking 'Indicated MPG's for a good number of years now, 

especially with ones where a up to temp car might be showing a very good Average MPG before filling up.  Just to see what it actually does after being into fill up.

I do it with each new car i get.

 

Maybe others with a petrol mk3 Fabia can say the maximum litres they have managed to brim their car up with.

Edited by Awayoffski
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Sorry guys but I really don't think it's a good idea running the car nearly empty,condensation in the fuel has been mentioned in this topic and along with other crap that gets into the tank may be drawn into the fuel lines when down to the last few litres in the tank, but each to their own.

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?

What is this crap that settles on the bottom of modern vehicles tanks, metal or plastic, is it rust, and does it get past the filter / pump and through the fuel lines really, 

is the tank outlet where the crap would be if there is crap?

 

Is this crap added to the tank from the filling station tanks via the fuel pump?

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sandman does make a good point. Nearly all of the crap that collects at the bottom of tanks in most cars is from the fuel drawn up from the tanks at garages. Garages go to some lengths to keep the tanks clean but over the years the water and dirt content in the tanks builds up. This collects at the bottom of their tanks. The worst thing you can do is then go to a filling station to refuel when that garage is taking in new fuel deliveries as the new fuel being pumped into the underground tanks (inspite of passing through baffles) 'stirs' up the dirt and water at the bottom of those tanks and gets sucked up by you into your car. Of course, you don't take on much as there are filters that the fuel goes through as it is sucked up but inevitably, some of that dirt and water finds it's way into you tank over time. Most gets trapped in your filters or remains at the bottom of your tank. I've stripped out tanks for replacement on cars, some only two or three years old and during draining I've seen all sorts coming out (no, not 'allsorts' sweets!). It's mostly dirt and water. Worse on some cars than others. In addition, it depends on what garage you are using. Some look after their tanks better than others and have a high turnover of fuel which is actually good. Other smaller garages may have slower fuel turnover, and may not look after tanks so well. There are variable on that which make a difference as to how clean the fuel you buy actually is. Fuel is actually filtered too on many sites as it goes into the tanks which helps greatly.

Edited by Estate Man
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Thank goodness that over years the industry moves on, modern filling stations get built as the old small ones disappear and there is Filling Station Maintenance and the likes because damage to customers vehicles is a very expensive thing and the adverse publicity not a great thing for Multi National Corporations or even just franchised filling stations.

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I can't see how running your tank down to near empty is going to make much of an improvement to overall fuel consumption :blink:

Can't say that my daughter's old 2003 Echo (Yaris) ever suffered from when she ran out of petrol, which she did on quite a few occasions. Fill it up from a Jerrycan and it just started, so any crud that must have accumulated still stayed in the tank and was not sucked through the system to cause any problems.

 

I've mentioned in other threads the quality of fuel sold in Australia is fairly poor with high levels of sulphur and a particularly evil 91 Ron Octane fuel that most local cars run on (not VAG cars of course).

Anyway BP are running a number of ads on the local TV channels claiming that running just two tanks of their high quality 98 Octane fuel with special cleaning detergents will clean out all the crud from your fuel systems. They prove this with animations of little Piranhas running through the tanks and pipes eating all the imaginary dirt which is supposedly destroying the car's performance and economy.

I'm seriously thinking of referring them to the Australian Advertising Standards Board.

 

 

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Thing is Gerry, BP's premium octane fuel does work. It has 1st grade detergents, and high grade additives that clean and dissolve the gum and dirt in the fuel system. It also has specific solvents that removes carbon and gum from pistons, valves, ports, and importantly, your injectors! It works and has been widely tested by the motoring press. Other companies also have their own versions with Shell being the other most effective fuel to clean your engine. Of course, they won't dissolve the grit that can build up at the bottom of your fuel tank over time. 

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I have not read these independent  verifications of the  efficacy of BP's fuel so you will have to forgive me for remaining a little sceptical about their claims.

So you are saying if I examine a fuel filter for its condition and then put through two tanks of BP 98 Octane then subsequent re-examination will of the filter should show considerable improvement?


There are legal standards that fuels need to meet and there is random testing for compliance at petrol stations. I did happen across an official site showing test results in Europe (inc UK) and non-compliance was thankfully very low.

Edited by Gerrycan
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  • 2 weeks later...

The topic of coasting or freewheeling (with the engine idling) cropped up in a  topic in the Superb mk3 section.

Freewheeling is a feature of the DSG box in Eco mode and I think in certain road circumstances it has potential.

Another contributor said this might work in Australia (where I live) but was not appropriate for the heavy traffic conditions in the UK and that braking using the gears to cover a distance with no fuel usage at all was a lot more suitable.

I don't disagree with that but I think each method has its advantages and should part of the economical motorist armoury.

Much easier in a manual equipped car but manageable with a DSG box by slipping in/out of Eco mode as appropriate for coasting or in-gear braking.

 

My reasoning was that both diesel and the small capacity tsi engines use about 0.5L/hour (or less) when idling (with no conveniences load) and that freewheeling at just 20kph yielded 113mpg so 40kph gave 226mpg and so on.

 

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Maybe like a lot of people out there, I still tend to use the gears while going down long steepish hills on the over run, though I probably shouldn't as brake parts are cheaper to replace than some other drive train parts.

So, while there are ways to improve your MPG - and that is important, maybe it is also important to avoid "accidentally" increasing your repair bills while doing this as at the end of the day it is "all up" costs that count?

 

Old SAAB 95/96s had a freewheel device and I don't remember hearing that lots of them suffered front end damage due to using the freewheel.

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It is still not a bad practice to use engine braking on long steep hills. If you depend only on brakes then most will overheat and become less effective in the event of a sudden stop being needed.

It was mandatory on the all drum brake equipped vehicles I learnt to drive on and I have never broken or wore out a gearbox yet through this practice.

The thing is that my 1.4tsi engine Octavia provides the least engine braking by far of any car I have driven. Be interesting to know if the Fabia is similar, smaller capacity engines but lighter weight.

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