Realword mpg figures petrol and diesel vrs

[jrw]

Hope Skoda have some even better technology in the pipeline.

They have, they've had it a good few years now, its called a diesel.

[lol-lol]

They have, they've had it a good few years now, its called a diesel.

Yes I have one of those too and enjoy it, especially as I have to pay for the fuel in that one!

Saw some proper performance diesels yesterday ie the Audi R10 and R18 at Goodwood.

My TSI fuel consumption started to return back to the 40 mpg as doing some proper long runs. Computer will reset soon as it hit 100 hours on the second trip.

When people do their fuel consumption figures are they using the fuel pump and the miles measured by the car as although the pump should be accurate due to weights and measures testing the mileage on the car could well be 5% out just like the speedo is to the GPS. Must compare mileage mneasured by car to SatNav as expect to see a few percent higher on the cat than SATNAV shows.

[jrw]

When people do their fuel consumption figures are they using the fuel pump and the miles measured by the car as although the pump should be accurate due to weights and measures testing the mileage on the car could well be 5% out just like the speedo is to the GPS. Must compare mileage mneasured by car to SatNav as expect to see a few percent higher on the cat than SATNAV shows.

Mileage off the odometer like 99.9999999% of all the people on the world will go by.....and litres at the pump. Again more excuses and tricks to try and get a higher MPG.

[eccleshill]

the pump should be accurate due to weights and measures testing the mileage on the car could well be 5% out just like the speedo is to the GPS. Must compare mileage mneasured by car to SatNav as expect to see a few percent higher on the cat than SATNAV shows.

The mileage on the odometer vs the sat nav is as near as makes no difference the same in tests I did on my last 2 Octavias. The error is built into the speedo to ensure it is always reading optimistic so you can't go complaining to car manufacturer when you get a speeding ticket cos you were doing 33mph when speedo said 30.

[lol-lol]

The mileage on the odometer vs the sat nav is as near as makes no difference the same in tests I did on my last 2 Octavias. The error is built into the speedo to ensure it is always reading optimistic so you can't go complaining to car manufacturer when you get a speeding ticket cos you were doing 33mph when speedo said 30.

Good to know. Occasionally one does get a useful nugget of a fact.

My main concern was that I might be putting it in for service hundreds of miles earlier than I needed to. Presumably the error that would be seen is the 2% due to the variation in the tyre fitments and tread depth.

[lol-lol]

Mileage off the odometer like 99.9999999% of all the people on the world will go by.....and litres at the pump. Again more excuses and tricks to try and get a higher MPG.

Post below reckons it is more accurate than the speedo which is good to know. Error rate probably of the order of 2% variance depending on tyre fitment and tread depth. Would be more accurate to use satnav disstance I suppose.

As I have said before it is not MPG I care so much about but range. I only pay 50p a litre for my private miles, less when I can transfer private miles to business miles.

Have not seen your acceleration curve print out yet, problem?

Tried to look at the GTI and HS websites but could not find the tables yet.

How did the diesels do overall? How many, any, in the top 50 quickest cars?

Any 1.8 TSIs to compare against the 170CRs?

Edited 5 July, 2011 by lol

[jrw]

Post below reckons it is more accurate than the speedo which is good to know. Error rate probably of the order of 2% variance depending on tyre fitment and tread depth. Would be more accurate to use satnav disstance I suppose.

As I have said before it is not MPG I care so much about but range. I only pay 50p a litre for my private miles, less when I can transfer private miles to business miles.

Have not seen your acceleration curve print out yet, problem?

Tried to look at the GTI and HS websites but could not find the tables yet.

How did the diesels do overall? How many, any, in the top 50 quickest cars?

Any 1.8 TSIs to compare against the 170CRs?

A quick look of this forum will show you that the results are on www.theresults.co.uk

As i said i did not get an acceleration cure print out and also as i said i linked to another thread to keep this on topic.

Didn't see any 1.8TSIs on there to be honest because, a) you made up a feeble excuse not to go and everyone has a VRS which is a 2.0

Also what does it matter about how accurate the speedo is? your speedo will be of the same accuracy of mine give or take 0.1-1% due to tyre wear. It is really neither here nor there to be honest and all you are doing is AGAIN making excuses for not posting results on fuelly.

Edited 5 July, 2011 by jrw

[Mark1967]

My 06 petrol with 145000 miles on the clock (yes 145000) still returns around 39-40 mpg on a steady run or about 27 mpg when i'm playing.

Mark.

[Stevoraith]

Jesus lol, everyone uses the milage on the odo, everyone will have the same error margins, just get on and do it and prove how good your TSI is.

[jrw]

Jesus lol, everyone uses the milage on the odo, everyone will have the same error margins, just get on and do it and prove how good your TSI is.

He's too busy 'massaging' the figures to eek the best mpg (or should i say false mpg)

[lol-lol]

He's too busy 'massaging' the figures to eek the best mpg (or should i say false mpg)

No, No just waiting for my accounts to forward me the figures.

Register reset on my trip to Liverpool today so was glad to see the back of the 39.5 average on there and it is now back to the 43 mpg I am use to seeing.

[Herschel]

I've just done a holiday trip from Brum to Dorset.

Fair bit of driving in Dorset too, so Motorways there and back, some country lanes, some town stuff in Weymouth, etc.

Tank and 3/4 later I'd done 1,108 miles.

Approximately, that's 49.5mpg over the week.

Now done 16,500 miles in it, so it's running in nicely.

Have had 64mpg on one motorway run at c.65mph.

[jdan]

1.8 TSI Scout. About 15,000 miles since new in March 2010. 40ish mpg on 'normal' country roads. 36 ish on motorways with cruise set at just about an indicated eighty. Drop that to 70 and the mpg gets better; 40 ish again.

Still love the car!!

[peanut18]

I'm not going to massage my figures or give optimistic readings. My TFSI fuel economy is dismal, I average about 28 -29 mpg and on a long run (if I keep it under an indicated 80) I might see 33 - 34 mpg. Would I change it for a diesel though...........not a chance. Diesel drivers may have the upper hand when it comes to economy, but having owned many VAG diesels I prefer the refinement and performance of a petrol everyday.

[barlborough]

I have a diesel estate VRS with theolder PD engine. Perhapss being a little anal I have a little book inthe car where I note the mileage, number of litres and price/litreeach time I refill and I always try to fill to the brim each time.

This data I transfer into a spreadsheeton my PC that works out both the MPG for the fill and the long termMPG for the car, as well as cost/mile etc.

MPG/fill is very dependent on how thecar has been driven, and can be effected if don't quite fill to thesame level each time, I have seen figures from 27.8 (but that was inthe snow) up to 54.3 (long run across France, normally between 42 and45MPG.

Long term MPG is currently 43.08, thatis for the full 3+ years I have owned the car. It has been increasingrecently – if I was to take it over just the last year or 6 monthsI would get a higher figure.

Strangely my long term average is justmarginally better than that displayed on the car computer.

Alan

[weyland]

I get 25-30 around town on short trips, and average around 37-38mpg on long runs sat on cruise with the car and boot full on family trips. For the level of performnace I consider that pretty good.

Diesels may have higher MPG, but they cost more to buy. The tolerances are so fine these days to achieve performance and high mpg that problems are common place and it only takes one of the many issues to wipe off any fuel cost savings you have made. I only do 7k a year so a petrol is a no brainer for me, your miles have to be right to justify the diesel, and they also aren't very go for stop-start traffic and short cimmutes due to the DPF - another headache to factor in.

Whilst my 25-30 commute (so average 27ish) might not sound great, for me that's only makes a few £ difference per week. For the enjoyment I get from the car it's well worth it.

[Bullit]

If you are in a newsagents/supermarket pick up and have a read of this weeks Auto Express. They have a petrol v Diesel debate and one of the examples is the Octavia in Elegance spec. A 2.0 Tdi DSG versus 1.4 TSi DSG.

Taking all costs into account to recoup the extra costs etc for the diesel you would have to cover 30,798 miles a year !

They also do an example using DSG estate VRS's you only have to cover 2124 miles before the diesel saves you money.

[lfc958]

If you work on the rule of 12k miles or less a year, then it has to be petrol, if its going to be over this then Diesel, I have used this as a general rule & it seems to work.

You also have to factor in your driving style, if you like to get to NSL quickly then youre going to trash any thoughts of economy, regardless of fuel type.

As you see from my fuelly below that is the real world average on my car which has done 5500 miles. My worst when I 1st got the car was 39mpg & am now getting close to 48, am hoping that after 1st servise i can consistantly get over 50mpg,

[jrw]

If you are in a newsagents/supermarket pick up and have a read of this weeks Auto Express. They have a petrol v Diesel debate and one of the examples is the Octavia in Elegance spec. A 2.0 Tdi DSG versus 1.4 TSi DSG.

Taking all costs into account to recoup the extra costs etc for the diesel you would have to cover 30,798 miles a year !

That is rubbish. Are they going off real world figures? VAG seem to 'sex' up the petrol figures as this makes them the most money as they are cheaper to produce. In my experience you get no where near the MPG figures quoted for the petrols (unless of course you are lol). Also i doubt they have factored in the cheaper road tax and less depreciation on the diesel.

[eccleshill]

That is rubbish. Are they going off real world figures? VAG seem to 'sex' up the petrol figures as this makes them the most money as they are cheaper to produce. In my experience you get no where near the MPG figures quoted for the petrols (unless of course you are lol). Also i doubt they have factored in the cheaper road tax and less depreciation on the diesel.

Don't know how they did it but I think they have used more than fuel cost.

Using list price and combined mpg from skoda.co.uk (£17,835 and 44.8 for the 1.4 and £21,025 and 53.3 for the 2.0), price of £1.40 for diesel and and £1.35 for petrol I calculate that to recoup the £3200 difference in price by fuel alone would take 180,000 miles. That figure shocked me! I have redone it 4 or 5 times and get the same answer - somebody please check! So they must have used more than just fuel and included overall running costs.

My 1st Octavia was a 1.9 TDI and over 3 yrs I achieved mpg of 88.5% of the quoted combined figure (51 vs 57.6 mpg. In my 1.8TSI DSG I am achieving 86.4% of the quoted combined figure (37 vs 42.8mpg). Limited data I know but I don't think it indicates any more sexing up of petrol compared to diesel.

I think the old rule of 12000 miles as the petrol/diesel breakpoint needs a rethink. It is no longer valid as petrol cars' economy improves while diesels are strangled by the addition of DPFs. Also the price differential between petrol and diesel is increasing - it used to be 2-3p per litre - it is now 5-8p per litre.

[eccleshill]

That calculation really disturbed me! Just did the same to compare petrol and diesel VRS manuals

Petrol VRS - List price £20,330, combined mpg 37.7

Diesel VRS - list price £21,155, combined mpg 49.6

Difference in list price £825

Assuming £1.40 for diesel and £1.35 for petrol

Fuel cost petrol - 16.2p per mile

Fuel cost diesel - 12.8p per mile

Difference is 3.4p per mile or £0.034

825/0.034 = 24,250 miles

So to recoup the price difference between petrol and diesel VRS would take total 24,250 miles just taking into account fuel. You then have to factor in higher diesel residual and lower road tax. That's more like it!

Looks like the choice of cars to compare has a significant impact on the result - need to be sure you compare apples with apples!

[jrw]

Don't know how they did it but I think they have used more than fuel cost.

Using list price and combined mpg from skoda.co.uk (£17,835 and 44.8 for the 1.4 and £21,025 and 53.3 for the 2.0), price of £1.40 for diesel and and £1.35 for petrol I calculate that to recoup the £3200 difference in price by fuel alone would take 180,000 miles. That figure shocked me! I have redone it 4 or 5 times and get the same answer - somebody please check! So they must have used more than just fuel and included overall running costs.

My 1st Octavia was a 1.9 TDI and over 3 yrs I achieved mpg of 88.5% of the quoted combined figure (51 vs 57.6 mpg. In my 1.8TSI DSG I am achieving 86.4% of the quoted combined figure (37 vs 42.8mpg). Limited data I know but I don't think it indicates any more sexing up of petrol compared to diesel.

I think the old rule of 12000 miles as the petrol/diesel breakpoint needs a rethink. It is no longer valid as petrol cars' economy improves while diesels are strangled by the addition of DPFs. Also the price differential between petrol and diesel is increasing - it used to be 2-3p per litre - it is now 5-8p per litre.

that seems a lot of cost difference between the petrol and diesel. Perhaps it is better compared against the 1.6 as the tsi is half way between the 2 with 122bhp but closer to the 1.6 than the 2 litre. Also not sure of the torque figures. 44.8 is laughable. Mother in law has a mk6 golf 122bhp. I was messing with the trip computer and noticed that trip 2has never been reset. The average on this is 38mpg. She never drives in rush hour and quite often does long drives over the country visiting people. I was shocked at this to be honest.

[jrw]

That calculation really disturbed me! Just did the same to compare petrol and diesel VRS manuals

Petrol VRS - List price £20,330, combined mpg 37.7

Diesel VRS - list price £21,155, combined mpg 49.6

Difference in list price £825

Assuming £1.40 for diesel and £1.35 for petrol

Fuel cost petrol - 16.2p per mile

Fuel cost diesel - 12.8p per mile

Difference is 3.4p per mile or £0.034

825/0.034 = 24,250 miles

So to recoup the price difference between petrol and diesel VRS would take total 24,250 miles just taking into account fuel. You then have to factor in higher diesel residual and lower road tax. That's more like it!

Looks like the choice of cars to compare has a significant impact on the result - need to be sure you compare apples with apples!

How did you calculate the cost per mile?

I work it out as 3.58p for the petrol and 2.82p per mile for the diesel??

[jrw]

~Found a calculator here that lets you put road tax etc in.

http://www.whatcar.com/images/subscription/petroldiesel.xls

the 1.6CR against the 1.4tsi would be 63k. If you change the tsi to 38mpg it becomes 37k. Thats without road tax and residuals.

Entering in the road tax and 50% depreciation on both over 3 years it works out that over 12k per year the diesel is costing less than the petrol regardless of real world or manufacturers figures.

The 2 litre however will not save you money unless you are doing 26k a year on manufacturers figures or 12.5k with the tsi at 38mpg!

Swings and roundabouts unless you know the real world MPG of your journey in both the petrol and the diesel!

[chr1staylor]

How did you calculate the cost per mile?

I work it out as 3.58p for the petrol and 2.82p per mile for the diesel??

Assuming we're talking about fuel costs you're way off there, it should be around 20p per mile for petrol and 15p a mile for diesel.