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Mpg Figures...


Mike77
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Cheers for those tips Kurt.

Previous £35 worth of fuel returned 53mpg overall, following my runs up to Wooler and back.

I fuelled up this morning, and am giving Shell a go, and have registered a loyalty card.

Nearest Shell filling stations to work are 3p/litre more (1.38/litre) expensive than the Tesco I had been using (£1.35/litre), but will be interesting to see if the 'Fuelsave' diesel does indeed make any difference, coupled with my (hopefully) better driving style.

Dad has my car tomorrow to fit some rear parking sensors for me, and I'm gonna get him to check the air filter and see if it looks like it needs/is worth changing.... as they say... 'every little helps'!

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My average mpg in london is 46, this is not impressive at all and it's near impossible to drive in heavy moving traffic with economy in mind i do try however but every so often it gets booted more than i want to. (This is with the car fully loaded in the boot)

1. When it comes to mpg it is important to note that no two engines will produce the exact same figure, the tiniest of variation in the build process will affect the on road performance.

FOCA - Modern cars are made to fine tolerances, and the same model leaves the factory, essentially, identical (apart from optional extras etc) higher milage cars (of the same model) can differ significantly, depending on use/ servicing etc

2. Weight makes a huge difference, i have a full size steal spare tyre (Sucks) getting rid of the extra weight is a must, get your "No fat chicks" stickers prepped.

Agreed, especially round town or accelerating/ decelerating or uphill, at a steady speed on the flat, not so much

3. Extras, some of us will have extras on our cars that adds massive amount of weights, like heated seats! heated seats or electric adjust seats are very heavy! The extra wire looms and what not that the titanium have that aren't use adds weight.

FOCA - Agreed, in general, its not what you might expect, though, door skins are negligable, full size 5-stud spare / jack = 20kgs any load on the electrics (anything heated is a big load, seats, windscreen etc) the heaters in the seats are light,as are the wires, but are a high electrical load, this puts a bigger load on the alternator, increasing mechanical drag the motor and mech for raising/ lowering the drivers seat only weighs 1kg

4. Runnings electrical equipment, this goes without saying... AC will lower mpg we all know this, but so does the blower, headlights and pumping stereo, put all of these together and you may find despite of your careful driving you can never achieve your ideal mpg. (Whenever talking about AC, do not open your windows and turn off the AC on the motorway, this creates drag that kills your mpg. Use AC at high speed and close your windows, the higher revs and speed will aid to AC to use less power)

FOCA - Agreed about the electrical loads but you must know what uses a lot, and what uses a little - (some electrical items use 10 times as much as others). as above, any electrical loads are eventually drawn from engine power via the alternator. In independant tests, open windows (even fully open) made very little difference at low or high speed, at a high steady speed, the AC hardly affected the MPG, accelerating/ rownd town, the AC had a big negative effect on MPG

5. service service service. you can never over service a car.

FOCA - agreed!

6. Fuel types. Now this will always trigger strong opinions but here is mine. Shell fuel kicks @ss, forget anything else, Shell fuel is no gimmicky marketing crap it really does increase your mpg over other fuels try it for your self.

FOCA Lets not go there! why? the cheapest fuel you can get might be the cheapest to run too

7. Get your self a Shell fuel card. It's simple, once you have your card you swipe on each fill up, end of. shell sends you vouchers in the post, next fill up you swipe your card and voucher, instant money off, there is no BS waiting around there is no jumping through hoops or calling some strange 0845 number to claim your discount. Money is simply minus from the fuel on the spot, last time my £60 fill up was £45 using vouchers.

Since i am self employed and calculate my mileage and fuel cost for tax purposes, i can tell you it makes a huge difference regardless of how crappy your mpg is.

FOCA - You probably pay more in the long run

8. As others have said, tyre pressure is very important. Low resistant tyres are also a must on your next tyre shopping list, forget the budget tyre or something from your local kwik fit, invest in some performance low resistant tyres it's money well spent. Get your tyres well balanced and tracked. From experience i find this to be something that goes a miss very easily. Ford does free tracking!

FOCA - Low rolling resistance "economy"/ "eco" tyres are one thing (yes they can make a significant difference to MPG) they don't have a lot of grip though grip = drag (you can get them with a good compromise MPG vs grip). "performance" tyres are a tottaly different thing - made for wet/ dry grip performance - not for economy - i always ran very high pressures (38-41PSI) i like the "feel" and i thought it would make a big difference to MPG - in an independant test, low or high tyre pressures did not make a significant difference to MPG - the tyres may have had a stiff sidewall though (tyres with softer sidewalls may have produced mor drag/ less MPG )

Lighter wheels and narrower tyres can make a big improvement to MPG - some cars have two sets of official MPG figures depending on the size/ width of wheel/ tyre fitted, on most modern cars the wheels are too wide for the power (eg small engined Fucuses or Fiestas with big, wide wheels/ tyres) fitted for "looks"

9. Get rid of your roof rack if you have one of course. i know it can be hard to gather the effort to do so especially when some roof racks are fiddly. Handle your biz like a man.

FOCA - I always thought this too (i got rid of my rack/s) - the modern "aero" racks/ roof containers don't seem to make that much of an impact on MPG, though apparently.

10. I don't have one :- )

FOCA - Driving style - choosing your route carefully/ when you drive, eg avoiding traffic etc (if possible ) hypermiling techniques knowledge- can make a big difference

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If you have two routes to work, one is a country road based route, and the other a motorway, opt for the country road route and give it a try!!

I personally do this, and have been watching my MPG. Motorway, constant speeds 70mph offers around 38 mpg, It I was at any point to get up to 80 mph that may, or may not offer around 41mpg. Country road route, offers a variable between 44 and 46 mpg. This is because the roads vary and I spend as much time with my foot off the throttle and rolling in gear as I do gently applying to go up and down the hills. There's no overtaking, so no sudden bursts of fuel being thrown in, and for me it works out better to do the country road route... Thankfully also in my situation, there is absolutely no time difference in travel the mileage is barely any different and it works a treat!

Although as Andy Dibley knows, and as I very nearly found out this morning, the country roads offer slightly more wildlife to contend with!

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very interesting read foca.

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very interesting read foca.

Thanks! The Autoexpress was a bit of an eye- opener! i always used to close my windows thinking leaving them open would have a disasterous effect on the drag, abd the MPG (i just leave them open when i want now), and i had my AC removed, i thought it would help the MPG, all round, not just accelerating/ round town (the AC system is 11kgs on the Mondeo, there is a pulley that always turns with the engine, so the AC delete is more than just switching the AC off)

The A.X. article is simplified, and they did not try different tyres (or wirths/ profiles) they tested at a constant 60, 70 and 80, but not at 30 40 or 50, they bundled the overall findings together, without seperating round town/ hill course/ motorway croising (eg round town the AC had a massive negative impact on MPG, but on the motorway at a constant speed, putting the AC on made hardly any difference to the MPG) a heavy weight in the car had a big negative impact on MPG when accelerating, and on the hill course so it depends on the conditions - the results were over-simplified (dumbed down)

Another surprising thing was when coasting up to junctions etc if you put the car into neutral the engine uses fuel to keep ticking over - if the car is in gear it uses no fuel as the ECU cuts the fuel supply - (this is when you are slowing down, coming up to an obstacle, going downhill etc ) - saw this on top gear. :)

There must be an optimum speed for maximum MPG - it differs between cars but on most cars is probably between 45 - 65 mph on flat ground (depending on gearing etc) - but driving too slowly car rouin your MPG too

If im stopped at traffic lights that i know are going to be at red for a while, i stop the engine, (or stuck in a traffic jam etc)

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Little update on my Focus.... Dad had it today, fitting my rear parking sensor kit, and checked the air filter.

Apparently it is very dirty, and actually had quite a few leaves stuck in it too.

So it looks like it hasn't been changed since the last service about 2-3 years ago, at least!

So, going to get a replacement filter and put that in, which will hopefully add to/help the fuel economy. Not going to the expense of a K&N filter though, as have read a few differing opinions of those - some suggesting that in letting more air in, they also let more debris into the engine too.

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FOCA I disagree with the idea that Shell fuel may be a way of paying more, like i said i have calculated it from my own driving, been doing so for the last two years. as with anything you can always shop around, that means fuel stations too, not all Shell stations are same of course and it will vary depending on distant for people to decide if it's actually worth doing or not.

Let me drop some calculations as an example using the 3p difference that johnson has seen between the Shell gas station and Tesco's gas station.

I will use my local gas station prices, REAL world prices

Say you fill up twice a month with 45 litres, that's what a full tank or just under?

Shell £1.48 per litre

Texaco £1.45 Per litre

Shell: £1.48 x 45 = £66.60 With two fill ups per months for a year you would have spend £1598.40

Texaco: £1.45 x 45 = 65.25 With two fill ups per month for a year you would have spend £1566.00

The difference is £32.40 a year spend on shell fuels, Now completely ignoring that i have said you can do more miles on shell fuel and only think of the difference with cost, i can tell you that, shell would give more than £32.40 in vouchers within 12 months for this amount of points earned.

Therefore over time shell fuel will be cheaper assuming points are collected.

Plus the added benefit of more miles done per gallon (Of course this is questionable, we all drive differently) Also sometimes shell is cheaper than others.

I also disagree on the subject of low resistant tyres having less grip. I don't know where you got this from but if you do some research you will find that top brand low resistant tyres such as goodyear, michelin, Continental, dunlop etc have the highest rated grip (based on the current lettering system) in wet, dry and braking. Visit www.mytyres.co.uk filter tyres based on low resistant. You will no doubt find these brands making tyres scoring A's and B's on grip, at extremely competitive prices.

Low resistant tyres also wear slow therefore lasting longer

www.mytyres.co.uk provides very reliable trusted info, although you can find the same info else where. Good website and prices highly recommended.

I would never suggest thinner tyres for better fuel economy, it's a fine line between saving money and your safety or your family.

On the subject of engines, engines are machined... these machine generate wear on the cutting part.... There will be a difference between the first engine machined on a new blade to the last engine machined on that same blade. Some of us will get engines at the top end some will get engines at the low end of the satisfactory margin.

Thank you for sharing the link FOCA, i wasn't aware at all that coasting uses more gas than being in gear... of course it makes sense

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On the subject of engines, engines are machined... these machine generate wear on the cutting part.... There will be a difference between the first engine machined on a new blade to the last engine machined on that same blade. Some of us will get engines at the top end some will get engines at the low end of the satisfactory margin

There may be considerably less difference than you imply. I would imagine that modern n-c machines will be programmed to take account of cutter wear. The various components will also be measured and matched to give almost identical fitting clearances so there should be little difference in performance of a batch of new engines.

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Sadly independant scientific tests have proven the Shell fuel to be correct regardless of what people think supermarket fuel contains a higher percentage of cleaner and as a result does not burn as clean this robs tge engine of power so you use more fuel cleaner burning fuel optimises the engines power so you use less.

Over all the cars ive owned all were better on Shell its all ive used for years i get better mpg thats simply fact the engine is far happier my mate also does vehicle recovery and poor running cars especially diesels using supermarket fuel have been better with premium fuels my old mans citreon runs on Shell after he was unhappy with the performance using asda fuel after a few tanks of shell he was happy fifth gears test proved it works as has independant tests also older low resistance tyres wear quicker and do provide less grip newer designs with better materials are as good as standard however theres thousands of complaints that they require replacement far too soon and given the cost therefore are a false economy when new they seem fine but dive off the cliff once worn and lets be honest if they worked as good as stated all manufacturets would have them fitted as standard and they dont simple marketing really a good way to eek money out the motorist buy more expensive tyres in the hope it saves you a few pounds worth of fuel

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im getting 32mpg overall 1.6 zetec 100 although mostly pottering about around down and a couple of dual carriageways did notice it getting much better on a motorway run.

On the subject of supermarket fuel my punto evo which i had prior to the focus would literally shudder when stationary on tesco/sainsbury fuel the mrs used to fill up in either for the weekly shop now i go to the esso down the road the day before shopping day it did get marginally better mpg but more importantly stopped juddering

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Thats the issue my recovery mate gets a lot and changing from supermarket fuel always sorts it petrol and diesels my sisters pug was the same she used bp fuel and problem sorted so those who say its the same it just isnt

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Johnson, changing the air filter makes a cracking difference

driving combo of country roads and motorway the last few weeks averages 41mpg,changed air filter yesterday whilst on lunch and got 46mpg on the way home.

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I .

I
I disagree on the subject of low resistant tyres having less grip. I don't know where you got this from but if you do some research you will find that top brand low resistant tyres such as goodyear, michelin, continental, dunlop etc have the highest rated grip (based on the current lettering system) in wet, dry and braking. Visit www.mytyres.co.uk filter tyres based on low resistant. You will no doubt find these brands making tyres scoring A's and B's on grip, at extremely competitive prices.


FOCA -
I presume you mean "low rolling resistance" tyres by "low resistant"?

Everything else being equal, the more grip a tyre has the more drag - so more grip = more drag / less grip = lower drag

Tyre manufacturers are developing ways of improving the economy (lowering the rolling resistance) such as stiffer sidewalls, and different materials such as increasing the amount of silica in the compound, this reduces drag but makes the tyre hard (and less grippy) at low tempratures (eg - under 7 degress C) making them unsuitable for winter use

The tyre has to be a compromise between wet/ dry/ cold temp grip and rolling resistance - "ultimate" eco/ fuel saving tyres do not have a lot of grip, "ultimate" sports/ performance tyres have a lot of grip, but have a high rolling resistance so are not good for economy

Low resistant (meaning low rolling resistance/ eco) tyres also wear slow therefore lasting longer


FOCA - Exactly - because they havev a harder compound and less grip

I would never suggest thinner tyres for better fuel economy, it's a fine line between saving money and your safety or your family.


FOCA - Its >narrower< tyres (not "thinner") narrower tyres are less liable to aquaplane in the wet and better grip/ traction in snow and mud, often modern cars have tyres that are too big /wide for the car (in my opinion), the wider tyres increase the rolling resistance, the larger wheels are heavier so have a bigger rotating mass this larger mass has to be accelerared/ de-celerated thus reducing economy (and performance) it also increases the unsprung weight- as and example i run 16" 205/55 tyres on my Mondeo - these are narrower than the (18") ones on the ST-TDCI and are a lot lighter (17.4 vs 22kgs) the narrower, lighter wheels & tyres, help the economy AND the performance, the traction off the line is reduced, and the ultimate grip - but the tyres have a more progressive breakaway (more controllable on the limit)

Narrow tyres (same width as the Prius "eco" tyres) are fitted as standard to the new Toyota GT86 (for better handling! :lol: )

Thank you for sharing the link FOCA, i wasn't aware at all that coasting uses more gas than being in gear... of course it makes sense


FOCA - No worries - As far as im aware i am the only one on the forum with a "seriously" eco-modded car (eco+ performance hybrid) that runs on sustainable fuel (veg oil) - i am learning all the time about hypermiling techniques/ modifications - the tyre facts i learnt many years ago, when i was a race engineer - not from google/ online but from actual practical experience (i would not consider myself a "tyre expert" though but i can tell the difference between BS (there is far too much online) and actual facts mostly :lol: )
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Well said foca.i've said for years that cars are running on tyres that are to wide. Why does a focus (for example) need to run on 205 tyres.

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What about the dramatic increase in braking distance?

Tyre deformation under load with narrower tyres?

Wider tyres spread the load and improve many things, for a car and weight the size of a Ford Focus, i think 205's are spot on.

is this not a worthy point to ad in on the topic of narrower tyres? it's been left out in your post and i believe better stopping power is more important than saving a couple of quid.

Decide between the cons and pros of eco tyres and narrower tyres. You only have to be let down by a tyre once and it will change your life.

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What about the dramatic increase in braking distance?

Tyre deformation under load with narrower tyres?

Wider tyres spread the load and improve many things, for a car and weight the size of a Ford Focus, i think 205's are spot on.

is this not a worthy point to ad in on the topic of narrower tyres? it's been left out in your post and i believe better stopping power is more important than saving a couple of quid.

Decide between the cons and pros of eco tyres and narrower tyres. You only have to be let down by a tyre once and it will change your life.

I think we have covered most of these points -

There are many factors that determine braking distance, a narrower tyre has less tendency to aquaplane in standing water, so in these conditions braking distances will be shorter, making narrower tyres safer for you and your family

as well as better grip in snow, mud and ice (when you really need grip)

Tyre deformation is more to do with the design/ construction of the tyre/ sidewall stiffness and other factors rather than tyre wirth

The point is to choose a tyre width/ wheel size that is appropriate for the weight / size/ power output of the car, and many modern cars (even small light ones with small engines) seem to be fitted with wider and wider tyres, almost as an appearance of "fashion" thing

Making the tyres bigger/ wider than nessesary does not make the car better or safer, wider tyres can give a harsher, noisier ride, "white line" in the wet (+ the previously mentioned tendency to aquaplane and reduced grip in snow/ ice and mud) - so how does that "improve many things"

This is only one small factor in the overall MPG equasion, though

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I'm not saying to compromise no safety or anything else. Surely the technology these tyre company's have today cars should be able to run around on narrower tyres..anybody ever thought the tyre company's and "in" with the fuel companys,so wider tyres keeps the mpg down.

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Well, will be close to refuelling tomorrow and the car looks like its now averaging approx 47-48mpg (both on the trip computer and mathematically) for my weekly commute mileage, which is getting nearer to what I'd hoped for (50mpg) when I bought the car.

Changed the air filter on Friday of last week (just a standard filter from EuroCarParts), and will be fuelling with Shell again this week, so see how it goes for a full week with a new air filter, but the small changes are making a difference for me.

Will also check the tyre pressures, and make sure they are kept right, too.

Cheers again for everyones advice.

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I would say a nice clean air filter will probably give you about 4 - 6 MPG (based purely on my own figures) boost (really depends on how dirty your last one was!)

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I would say a nice clean air filter will probably give you about 4 - 6 MPG (based purely on my own figures) boost (really depends on how dirty your last one was!)

Thats a lot! i would have only expected 2 or 3 MPG - must have been pretty clogged (i fit a new (cheap pattern one) one every 6 months)

The ECU adapts to the cloggeg filter (to an extent) re-setting the ecu (watch you don't loose your radio code) can help the economy, and often the performance

Are you noticing an improvement in performance too?

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The filter that came off was pretty scruffy, and when my dad first inspected it (whilst fitting rear parking sensors for me), he said it had loads of leaves in it too, which he cleared out. So I'm guessing it hadn't been changed for at least a couple of years.

In terms of performance, i haven't noticed it much, but I'm trying to drive better anyways to help the MPG, so not 'putting my foot down' too much. But it certainly has the pull when I've need it to overtake someone on the m'way.

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its amazing what allowing the car to breathe will do for you!

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its amazing what allowing the car to breathe will do for you!

Especially on diesels they suck in a lot more air than petrols

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definately. And yes Foca, it was a mess, I have a picture somwhere but I removed leaves amongst other things. the country road route I use to work previously averaged about 41MPG, now on that road, I can see up to 52 MPG with exactly the same driving style and speeds.

The motorway of course sucks that up, butI saw that the combination of Motorway and A roads where giving around 38-41 MPG. Now I get the best part of 45MPG, or if I drive economically as I did yesterday, I saw about 49.9 MPG averaged across the journey!

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