Petrol vs Diesel - the dilemma if annual mileage changes from high (> 18,000) to low (< 5000). This may be of some interest for anyone considering between petrol and diesel. In April 2024 I replaced my 2013 2.0 TDI DSG VW Touran after 108,000 miles with a 2023 2.0 TSI DSG 4x4 Karoq. Low annual mileage, in retirement, didn't suit the diesel.

Now after 18 months I can compare fuel costs, my gut feel back in 2024 was that whilst the mpg of the petrol was worse this would be offset by the lower price per litre. Analysis of the fuel purchased over 12 months compared with the diesel Touran over 12 months is as follows:

Petrol Karoq 6.53 miles per litre, over approx 6,500 miles

Diesel Touran 7.10 miles per litre, over approx 5,200 miles

Using Shell V Power fuel in both - the diesel would cost 50p more per 1,000 miles. negligible difference.

I used only V Power diesel in the Touran and use Shell E10 Unleaded in the Karoq saving £22 over 1,000 miles. I think this confirms my original thinking was valid the fuel costs of the petrol Karoq running E10 costs less than the Touran running V-Power Diesel on the type of journeys I now do. Its not a perfect comparison - the Karoq is heavier, not such a smooth shape and has the extra drag of the 4x4 transmission, comparing petrol and diesel 4x4 Karoqs would I think show a greater saving with the petrol engined one.

I've not included the extra cost of Ad Blue as the 140 bhp TDI in the Touran did not use Ad Blue, this is a further cost which would need to be include and increases the overall cost per 1000 miles for the diesel.

Pre retirement the Touran was doing 17,500 miles per year and averaging 11 miles per litre - its a no brainer - even using V Power the diesel is still cheaper on fuel than the best mpg the petrol could possible achieve.

I did the same guess calculations a while ago. I had a Diesel Primera 2litre when working and travelling across the UK, the wife had a petrol 1.4 Nissan Note. The Primera went first (it was 18 years old) when I stopped working as, thanks to Covid it ended up on the drive 99% of the time. Post Covid things didn't ever come back to "normal" before I retired. We used the petrol Note for a year or two thinking we need to replace it as it was 14 years old.

Most of our mileage, a lot lower than when working, is short distances around town with occasion runs on dual carriageways and motorways of 40 and 80 miles each way to visit relatives. So I went for a 1.5 Petrol Karoq.

Over this year we are averaging 41 MPG with a range of 37-44mpg over the months according to the Skoda App.

The other factor was that we are close to Birmingham Costco. At the moment not only is unleaded less than Diesel the E10 is 1.24 a litre.

At 7.10 miles/litre in the Touran that works out at about 32mpg! That's petrol territory, and at 6.53 miles/litre in the Karoq is just under 30mpg, so hardly any difference - or have I worked something out incorrectly?

Just wondering why the Touran was so thirsty for a diesel, my Superb 2.0 TDI DSG averages 60mpg, quite impressive given the size of the car.

21 minutes ago, cnc said:

my Superb 2.0 TDI DSG averages 60mpg, quite impressive given the size of the car.

indeed it is. what sort of driving is that?

26 minutes ago, cnc said:

At 7.10 miles/litre in the Touran that works out at about 32mpg! That's petrol territory, and at 6.53 miles/litre in the Karoq is just under 30mpg, so hardly any difference - or have I worked something out incorrectly?

Just wondering why the Touran was so thirsty for a diesel, my Superb 2.0 TDI DSG averages 60mpg, quite impressive given the size of the car.

Your maths is correct - I was doing 2 or 3 journeys a day of about 2 to 3 miles each - why didn't I walk - I probably should have done! It never warmed up really. It was all round Milton Keynes 70 mph dual carriageways with roundabouts every 1 kilometer. On long runs the Touran would average 60 mpg easily and over the first 90,000 miles averaged 50 mpg. I think the diesel was thirsty whilst getting to a speed, and economical once there.

This summer I did a 1000 mile trip to MK to Aberdeen and back towing my classic car on a two axle trailer. The KAroq averaged 30mpg the Touran did the same trip in 2019 averaged 35 mpg - both times I was travelling at 60 mph on the motorways using cruise on the Touran but Speed limiter on the Karoq which allowed it to coast quite a bit.

2 minutes ago, chills said:

indeed it is. what sort of driving is that?

Mostly longer journeys on motorways using cruise control at a steady speed, so pretty much ideal circumstances for a diesel, covered a little over 33,000 miles so far this year @ 60.1mpg average.

I was converted to being a diesel fan back in 2000 when I ordered a petrol Espace, and the agent delivered a diesel. It was great for 7 years but at the end it couldn't get 40 mpg and any acceleration produced a huge cloud of black smoke. My last diesel was a 2.0HDi Citroen Picasso, which we used for continental trips to Austria every year. This was of the earlier cars with Adblue, and of course I was one of the first into the workshop with the Adblue failure. We loved the car, but if there was a problem with them, we had it, but at least it was all covered by either warranty or recall. In normal use, the car would do ~48mpg, and on holiday runs about 52mpg. Wedecided after 6 years to let it go and bought our current 2.0TSi Karoq. This, like the Picasso, does between 48 and 52 mpg and runs beautifully at the speeds I like to drive. So, as the mileage per gallon is almost identical and diesel locally being 5% more expensive than diesel, I estimate my Karoq is cheaper to fuel than the Picasso. I don't have to but Adblue, worry about filling it or running out on the continent (my filler was under the boot floor, so not convenient if you have a bootfull of luggage), and I don't have to worry about the inconvenience (or £1000 cost) of having the pump fail. As far as performance goes, my only issue is the pitifully low torque the engine provides at low engine speed, especially if the aircon is on.

Edited 14 November, 202514 Nov by Routemaster1461
Correct typo.

@thamestrader Is it Shell V-Power 99 ron Superunleaded which is E5 you use or Shell Unleaded E10 (95 ron) ?

52 minutes ago, Routemaster1461 said:

Deleted duplicate

Edited 14 November, 202514 Nov by Routemaster1461

There were various factors that came into play when I decided on a petrol rather than diesel in 2018. At that time I was doing 16 to 20 thousand miles a year. I had a 2010 2.0 Tdi Yeti that was perfect for my needs.

The Yeti was totally ruined after the 'fix'. Prior to the fix the dpf would regenerate passively so that I never knew it was happening. Post fix It would regenerate often at the end of a 50 mile journey. I would then unload the car and go out again to make sure the regeneration was completed.

Another consequence of the fix was that it caused problems with the EGR valve. VW accepted this and I had it replaced free even though the car was well out of warranty. However the replacement valve only had a 2 year warranty. I was coming up to the end of this warranty and I was not prepared to take the risk of paying for a replacement (around a £1000).

These two factors were the main reasons for changing to petrol. I had lost faith in diesels. My Yeti was in for a service and MoT at Vindis Bury St Edmunds and they had a pre-reg 1.5Tsi DSG Karoq SeL. On a whim I took test drive, liked it, and bought one.

As my annual mileage was reducing (now doing under 5,000 miles a year) petrol was the perfect choice. With my Yeti doing the higher mileage I was getting around 48 mpg. My Karoq, that sits on the drive a lot of the time, beats 30mpg on very short trips to the supermarket and gets around 44/45 mpg on dual carriageway journeys. I'm happy.

Lastly, and nothing to do with the petrol/diesel question, when in 2018 I decided to get rid of the Yeti I kept an open mind despite being seriously disappointed with VAG. A big factor in staying with Skoda was the quality of service I was getting from Vindis (no link, just a satisfied customer).

tom

The last diesel I had was a 2017 Yeti 2.0TDi 150.

My current 2024 2.0TSi 190 Suberb is around the same economy on urban trips and better economy on a run and petrol is cheaper.

The weights are about the same but the aerodynamics are worlds apart.

I went from a 2012 Octavia vRS CR to a 2.0 tsi sport line 4x4.

The Karoq on a steady run will do mid to high 40s, the Octavia would do mid to high 50s.

I tow a caravan. The Karoq is a much better tow car and the towing mpg is very similar to the Octavia.

I used to do about 15k a year when working. Now do about 7k.

The diesel just didn't make any sense for the mileage I do now.

With the price of unleaded Vs diesel I'm not that much worse off.

22 hours ago, Evolution13 said:

@thamestrader Is it Shell V-Power 99 ron Superunleaded which is E5 you use or Shell Unleaded E10 (95 ron) ?

@Evolution13 in the 2.0TSI Karoq I initially used Shell E5, then switched to Shell E10, now back on E5. I haven’t yet analysed the mpg data. The round trip to Aberdeen was all Shell E10, the Touran always used V Power diesel. We have a 2015 1.2 TSI Fabia which is always filled with Shell V Power E5, I’m sure it makes a difference - I think I’ve commented on this in the Fabia subforum.

My wife had one of the last of the mk1 Tiguans in 2015, so it had the then new 150PS Diesel with Ad Blue, with DSG and 4Motion. She switched to the 1.5 150PS DSG Karoq a couple of years ago.

Her use is exactly the same - semi-rural trips of a few miles to the shops, picking grandchildren up from school etc. I spreadsheet the MPG and the long-term average is exactly the same - 38MPG. Of course the Tiguan was 4Motion, and for most of its life it used V-Power, then switched to Costco stuff. Use standard Costco petrol in the Karoq.

@Sanqhar I did not have the diesel fix applied to my Touran. Even so it eventually succumbed to EGR valve failures. Up to 2020 it had done around 94,000 miles, reduced use during Covid resulted in the EGR failing in Oct 2020 after 96,000 miles. It failed again at 104,000 miles 3 years later.

I've now analysed the fuel consumption when using Shell V Power (E5) and Shell Fuelsave ULD (E10) fuel.

Fuelsave E10 from 1144 to 2659 and 6706 to 10903 total 5682 miles 6.36 miles per litre or 28.90 mpg. May 24 to July 24 and March 25 to end October 25.

V Power E5 from 2659 to 6706 total 4047 miles 6.60 mile per litre or 29.95 mpg. Mid July 24 to mid March 25.

The V Power mpg is 4% better than Fuelsave unleaded and the price per litre is 25% higher. The V Power was used over winter so that may have reduced mpg slightly, also engine and transmission are now 'run in' so that may also improve mpg marginally.

That's interesting.
So my decision to go petrol over diesel and use E10 seems justified.

2 hours ago, chills said:

That's interesting.
So my decision to go petrol over diesel and use E10 seems justified.

I can't recall where I saw it now, someone had posted details of the actual Ethanol content of the various petrol brands. That was quite interesting as some of the premium brands E5 and E10 contained less Ethanol than other brands., as the requirement is up to 55 or up to 10% .

9 hours ago, thamestrader said:

I can't recall where I saw it now, someone had posted details of the actual Ethanol content of the various petrol brands. That was quite interesting as some of the premium brands E5 and E10 contained less Ethanol than other brands., as the requirement is up to 55 or up to 10% .

I tend to use either Shell V-Power E5 or Tesco Momentum E5. Both on multiple tests have been shown to contain zero ethanol.

10 hours ago, thamestrader said:

I can't recall where I saw it now, someone had posted details of the actual Ethanol content of the various petrol brands. That was quite interesting as some of the premium brands E5 and E10 contained less Ethanol than other brands., as the requirement is up to 55 or up to 10% .

As far as I am aware the ethanol content of E5 and E10 is variable within batches of fuel. As all fuel comes from large tanks in the refineries, all brands filled from those tanks will have the same content, the difference between brands being the additives. This may vary between batches. The proportion of ethanol can vary significantly between refineries, so there may be significant differences between the ethanol content of E10 between, say, Esso bought in Southampton (ex Fawley) and Scotland (probably ex Grangemouth)., but Shell in the same locations may well be the same.

I am not sure comparing a diesel 2wd with a petrol 4wd is fair.

The 4wd drive system adds 130-200kg depending on model. Its the equivalent of driving around with about 5-8 25kg bags of cement as deadweight permanently in the boot.

You cannot distort the weight by around 10% then run a simple comparison of fuel costs.

.

Edited 19 November, 202519 Nov by SurreyJohn

Plenty threads on here over the past years and how the Bio-Ethanol in E5 can very by Producer / Distributor or the Depots / Regions. From 0-5% Bio Ethanol. The TSI,s love the Bio-Ethanol and cold air. & the Formulation changes late October to March in the UK, starting oop north first.Itis less hygroscopic.

If you are filling up with Tesco Momentum 99 (99 ron min) in Scotland this winter it might well be 100 ron Plus and the Same winter E5 as bought on mainland Europe. But that can be the same anyplace in the UK. The base fuels are often stored after import along with Royal Dutch Shells fuel. & is not from UK refineries. Then there is the additives, and where these depots are.

On 14/11/2025 at 10:19, Routemaster1461 said:

our current 2.0TSi Karoq. This, like the Picasso, does between 48 and 52 mpg

48-52 mpg in a 2.0 TSI!!!
Flippin heck, I think I must have a very heavy right foot 😂

On 19/11/2025 at 08:23, SurreyJohn said:

I am not sure comparing a diesel 2wd with a petrol 4wd is fair.

The 4wd drive system adds 130-200kg depending on model. Its the equivalent of driving around with about 5-8 25kg bags of cement as deadweight permanently in the boot.

You cannot distort the weight by around 10% then run a simple comparison of fuel costs.

.

I agree its not the usual type of comparison. It’s a simple comparison of mpg of the 2.0 L TDI that I previously owned against the 2.0 L TSI that replaced it, for my specific usage pattern. It’s interesting that others have similar experience. Higher mileage with longer journeys though favour the diesel. I did a number of return trips to Bristol in the Touran and Karoq, the Touran did around 60 mpg the Karoq about 48 mpg, so very much horses for courses. Those journeys were 2 or 3 a year exceptions rather every week.