TFSI CYL ON DEMAND VS DIESEL ???????

dick wad

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Hey folks what are your thought's on this dilemma i have. I recently ordered my A3 S-Line 2.0 ltr diesel with way more extras than i can afford...... So, i thought, why not change to the 1.4 TFSI 140 Bhp Cylinder on Demand engine and save £1400. Problem is i have always had diesels and achieved way more mpg than when i have driven petrol cars. My daily travel to work is only a ten mile round trip. My trusty MK4 Golf TDI 130 always returned over 40mpg no matter how i drove it. I have driven the new Golf 1.4 TFSI 122bhp as could not find a 140bhp model and found it a bit gutless unless you rev it hard. Has any body out there had any experience of the Cylinder on Demand engine or the new 2.0 ltr diesel 150 bhp engine. It's hard to find demonstrators out there. I have to make a decision soon don't have a build date yet though. I found other threads on audi-sport that were of great help to me in making decisions on things like tech and sound systems thanks for that.
 
Have tried the 140ps COD engine in a Golf GT and it has much better acceleration than my 122ps A3 which I also find gutless. Fine on motorways and around town but call for acceleration and it takes its time.
I've done 2000 miles in my A3, varied driving and overall average is 46mpg - from day one
 
You may miss the low down torque of the Diesel engines, hence the gutless feeling in the petrol car.


Mark
 
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Petrol and diesel have a different feel to them and need to be driven differently. It's a very personal thing which you prefer. It sounds as if you are more at home driving a diesel so that's probably the best choice for you. (I'm the opposite - only ever enjoy driving a petrol). That said, the COD is very torquey for a petrol, if the figures are to be believed.

Edit: if you're getting it on a PCP, the COD may not be much cheaper in terms of monthly payments as diesels don't depreciate quite as quickly.
 
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Hello **** W, you may want to try to chatting with Moonlight. He has the COD 1.4 and he has had the car for circa a week so can at least given you some indication.

I have the 2TDI and it is a cracking engine. MarkWiggy above said earlier today he thinks the 2TDI is a belter of an engine. Great MPG early on and plenty of torque through gears 2-5. Unfortunately I cannot compare to the 1.4 140ps engine. Moonlight might be able to as I think he had a 2TDI Scirroco before the Sportback. Message him and ask him for his thoughts on the Cod and might be able to give a comparison with a 2tdi.
 
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Hello SJW, thanks for that i'll try chatting with moonlight. Thing is i guess most people tell me "unless your doing 12000 miles a year or more a diesel isn't worth it" i know driving styles are different for petrol and diesel but ultimately i think, if you drive them harder the diesel will give you better mpg. I just can't see the COD giving anywhere near the mpg Audi reckon.
 
I plumped for the COD because i dont like diesel engines. But i tried to do a bit of man maths to justify it....

COD: 46mpg for 10,000miles = 217 gallons used
cost (@135p/ltr or £6.10 per gallon) = £1,324

Diesel: 56mpg for 10,000 miles = 178 gallons used
cost (@140p/ltr or £6.30 per gallon) = £1,121

Difference in fuel cost over 10,000miles = £203
Miles required to pay back £1400 premium for diesel = 68,965miles!!!!

This assumes a difference in mpg of 10 between the two variants.
I think its shocking they charge £1400 more for a noisier, lazyer (yes it is) engine.
Even at 40mpg the COD is worth it as long as you sell around 50,000miles
 
I plumped for the COD because i dont like diesel engines. But i tried to do a bit of man maths to justify it....

COD: 46mpg for 10,000miles = 217 gallons used
cost (@135p/ltr or £6.10 per gallon) = £1,324

Diesel: 56mpg for 10,000 miles = 178 gallons used
cost (@140p/ltr or £6.30 per gallon) = £1,121

Difference in fuel cost over 10,000miles = £203
Miles required to pay back £1400 premium for diesel = 68,965miles!!!!

This assumes a difference in mpg of 10 between the two variants.
I think its shocking they charge £1400 more for a noisier, lazyer (yes it is) engine.
Even at 40mpg the COD is worth it as long as you sell around 50,000miles

One flaw in the calculations.... Most people don't keep their cars to the death so you have to consider the residual.

Arguably, the diesel will hold a little bit more but for the purposes of your 'man maths' we'll assume they depreciate at the same rate.

Let's assume they both hold a 50% residual over three years.... the difference between both cars is then £700. If that's the case, anything over 10k-12k per annum and you're into diesel territory on an A3. :moa:

Most people though will buy on other criteria. As you've said, you prefer petrol engines so the money side is kind of irrelevant as you'd never be happy with an oil burner.
 
We have indeed chatted.... the upshot of which is that I am only averaging 36mpg...but this is 90% urban...and I have been in some rather long dial tapping traffic.....I have a long run ahead of me this weekend and will advise further! I'm quite sure if left in efficiency mode and driven like Miss Daisy it would yield a good return but I got the car to be driven....filled up last night and its telling me a range of 410...which is 37(wahoo!)

They are 2 different types of engines..a diesel is never going to be as smooth or quiet as a good petrol engine (by good I mean Audi) and the 1.4t is never going to be as 'torquey' (is that in Devon!lol) as a diesel nor is it going to be as economical.....I would have been just as happy with either. Each to their own as they say....I could have had the sport diesel but thought it was well worth upgrading to the s-line and dropping down to the 1.4t..(thinking at the time it would be a compromise - and it really isn't....unless your loyalties lie with diesels that is)....I went from a petrol to a diesel years ago and thought how fantastic the diesel units were now I've done the reverse of that...both great engines though.
 
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I did the full calculations on cost over 3 years @ 15000 miles p.a. The diesel was about £300 cheaper, but I prefer petrol so that's what I chose.
 
Hitchy - yeah, 3 years! So worrying about a big difference in mpg isn't really worth it. It's very nip and tuck. Based on this it's fair to expect an equal rate of depreciation, unlikely though, making the cod an excellent 2nd buy for anyone after a three year old motor.
 
I'm a little bit sceptical regarding the fuel savings of these current COD engines over a standard petrol version. Seat have the standard 1.4 140ps petrol on their Leon, and as yet no official announcement as to when they'll get the COD/ACT variant, and already owners are posting real-life figures of mid 40s. If the COD version in the A3 and VW is returning similar figures then I'd be a bit disappointed.
 
The the standard petrol is good on the mpg, but lacks the power. If the cod has the same mpg but more performance, I'm happy. Also, it does drop the sportback car into the £30 tax bracket.
 
Overall I think the running cost difference is marginal between the two and over the course of 3+ years if you are worried about the equivalent to £10 - 15/month then maybe you should no be buying a brand new car in th first place as you loose £1000's as soon as You drive it off the forecourt, unless you have just bought someithng huugely popular and with a 5 - 6 month order book.

Seriously, my choice was based purely on performance I did not test drive a 1.4COD but the one thing I do not like about my current 1.4TFSI is the relative lack of torque at typical motorway speeds with 3 or more pople on board and intuitvely felt the COD might be a little worse even with the extra BHP. That is when you put your foot down when crusiing on a motorway it will take a bit longer to engage 4 cylinders, ignite the turbo and receive the power, compared to just ignite the turbo The 2.0TDI will not give me that niggly worry
 
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That is when you put your foot down when crusiing on a motorway it will take a bit longer to engage 4 cylinders, ignite the turbo and receive the power, compared to just ignite the turbo The 2.0TDI will not give me that niggly worry

:iagree:...however.......The entire switchover operation takes 13 to 36 milliseconds, depending on engine speed; switchovers are smoothed by interventions in fuel injection, ignition timing and the throttle valve.

In reality the 2-4 and 4-2 don't quite work the way you would imagine....or certainly not with my style of driving...there MIGHT be a SLIGHT delay if say you were plodding along and decided to stamp your foot down out of the blue ...in a zero to hero fashion but what tends to happen is that you either pre-empty the road ahead or again with my style of driving stay in 4 cylinders....it wouldn't drop into 2 say if you wanted to tear down the highway in 3rd or 4th....(3rd being it's favourite gear btw..as with many) and start overtaking all and sundry...and it would be pretty much the same in 5th and 6th depending on the speed/revs.....the only time it drops into 2 pots is when you are cruising and hardly touching the throttle...it only takes slightly more pressure to keep the 4 pots singing....it has enough torque to be able to accelerate in any gear.....obviously the diesel packs more of a punch torque wise (though not 0-62!)

The diesel and petrol(whether it be cod or not) debate could go on forever ...and it has....I've switched from petrol to diesel and back again and loved them both for different reasons...give me a 2.0T petrol that has the MPG of diesel and there'd no be no contest !
 
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Well, 24hours from now i will (hopefully) be driving the new motor for 3 straight hours on a motorway having picked it up. Hoping for zero noticable switch over from 2 to 4 cyl's, fingers crossed.
 
Well, 24hours from now i will (hopefully) be driving the new motor for 3 straight hours on a motorway having picked it up. Hoping for zero noticable switch over from 2 to 4 cyl's, fingers crossed.

You'll love it!
 
I don't think people give a rats **** about fuel efficiency, it's cost efficiency that people look for and for that reason, With diesel being more expensive to buy, noisier and lazier, I just can't see the appeal. It is personal preference, only I wish that people weren't lulled into thinking that diesels are much more cost effective.
 
Depends on your mileage. For the amount I do, it is. I also prefer the way they drive with all the torque, and they are much better for towing which I do a fair amount. I can't see the appeal of a screaming petrol engine that you have to rev the ******** off to get anything out of it, but each to their own :)
 
:iagree:...however.......The entire switchover operation takes 13 to 36 milliseconds, depending on engine speed; switchovers are smoothed by interventions in fuel injection, ignition timing and the throttle valve.

In reality the 2-4 and 4-2 don't quite work the way you would imagine....or certainly not with my style of driving...there MIGHT be a SLIGHT delay if say you were plodding along and decided to stamp your foot down out of the blue ...in a zero to hero fashion but what tends to happen is that you either pre-empty the road ahead or again with my style of driving stay in 4 cylinders....it wouldn't drop into 2 say if you wanted to tear down the highway in 3rd or 4th....(3rd being it's favourite gear btw..as with many) and start overtaking all and sundry...and it would be pretty much the same in 5th and 6th depending on the speed/revs.....the only time it drops into 2 pots is when you are cruising and hardly touching the throttle...it only takes slightly more pressure to keep the 4 pots singing....it has enough torque to be able to accelerate in any gear.....obviously the diesel packs more of a punch torque wise (though not 0-62!)

The diesel and petrol(whether it be cod or not) debate could go on forever ...and it has....I've switched from petrol to diesel and back again and loved them both for different reasons...give me a 2.0T petrol that has the MPG of diesel and there'd no be no contest !

So COD can almost totally be unused dependant on where you drive or your driving style (maybe thats why its not displaced in the A3 MMI - according to another thread) so potentially technology for the sake of technology (a bit like DAB if you only ever listen to 3 or 4 stations).

I do wonder how much VW have just pandered to beating the emissions test with the COD technology, that said it is pretty neat - 140bhp from an off the shelf-life 1.4 petrol engine, who would have thought you could one horse to every 2 medicine spoons of cylinder space

When I first got my 1.4TFSI I was very impressed and a French colleague who initially laughed at the 1.4T badge on the back was convinced I had it deliberatly underbadged after taking him for a spin.
 
I doubt there will be a huge improvement in MPG with the COD. Actually, if you drive it hard you'll probably get worse MPG from the COD, due to the increased performance.
 
No, probably not. The idea behind cod is to deliver more performance without a reduction in mpg and better emissions rather than the promise of vastly superior mpg.
Personally I don't drive harder just cos the car is faster, and I'm more likey to need to 'floor' the standard 1.4 more than the cod due to the extra poke and flexibility. This was obvious with my old 2.0 rs Clio. Driving to work everyday I'd get 40mpg, my colleague had a 1.2 Clio and managed 40mpg same journey (he literally used to follow me quite often). He floored it up hills in 4th and I was barely tickling the throttle. It literally depends on how much you press the loud pedal.
 
technology for the sake of technology (a bit like DAB if you only ever listen to 3 or 4 stations).

Or any stations at all, seeing as the analogue signal for radio will be being switched off some time in the not too distant future
 
Or any stations at all, seeing as the analogue signal for radio will be being switched off some time in the not too distant future

I believe they've kicked this into the long grass.... well past 2017. I reckon it'll be at least 5-10 years after they've legislated that all new cars MUST have DAB as standard.

Radio switchover delayed as listeners shun digital - Telegraph

4G integration may sound the death knell for DAB in many new cars. I'd rather use Internet radio as I do at home now.
 
The the standard petrol is good on the mpg, but lacks the power. If the cod has the same mpg but more performance, I'm happy. Also, it does drop the sportback car into the £30 tax bracket.
Actually the Seat's standard 140ps petrol engine is marginally more powerful than the Audi's.
 
No, probably not. The idea behind cod is to deliver more performance without a reduction in mpg and better emissions rather than the promise of vastly superior mpg.
Personally I don't drive harder just cos the car is faster, and I'm more likey to need to 'floor' the standard 1.4 more than the cod due to the extra poke and flexibility. This was obvious with my old 2.0 rs Clio. Driving to work everyday I'd get 40mpg, my colleague had a 1.2 Clio and managed 40mpg same journey (he literally used to follow me quite often). He floored it up hills in 4th and I was barely tickling the throttle. It literally depends on how much you press the loud pedal.
But this is the point I'm making. If the point was to produce a more powerful engine without comprising fuel efficiency then how come you can still have the same (if not slightly better) performance in the same 140ps engine without COD. Kind of defeats the point of having the tech in the first place, at least with this 1.4 engine at least. There's no doubt that COD works with the more powerful petrol units though.
 
If your driving along a motorway at 70 without Cod then ud be using twice the cyl's and twice the fuel, so it doesn't compensate for the times when u use all 140bhp. Overall Mpg would be less.
 
It's personal driving style and the types of roads you drive. I do mainly open roads steady 60mph commute. COD would be an advantage to me, but it might not suit everyone.
 
If your driving along a motorway at 70 without Cod then ud be using twice the cyl's and twice the fuel, so it doesn't compensate for the times when u use all 140bhp. Overall Mpg would be less.

Sadly I don't think it uses half the fuel. The remaining cylinders are working twice as hard so need nearly twice as much fuel each.
 
Well that is pointless then. Still, proof is in the pudding :)
 
The diesel and petrol(whether it be cod or not) debate could go on forever ...and it has....I've switched from petrol to diesel and back again and loved them both for different reasons...give me a 2.0T petrol that has the MPG of diesel and there'd no be no contest !

Hit the nail on the head,I would still be driving a S3,RS3 or awaiting the new S3 if either could return 45MPG average,but they can't hence me driving a diesel for the last 3 years. I love petrol engines but its just not practical for me anymore, the nail in the coffin for me was going on holiday to Devon in my S3 for 4 days, £200 petrol bill.

Mark
 
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Have tried the 140ps COD engine in a Golf GT and it has much better acceleration than my 122ps A3 which I also find gutless. Fine on motorways and around town but call for acceleration and it takes its time.
I've done 2000 miles in my A3, varied driving and overall average is 46mpg - from day one

I am surprised at your 46 mpg ... or mine ! I own a A3 8V TFSI 1.4 122 (S-Tronic) and my overall average from day one (3000 km now) is 42 mpg although I am the calmest and "smoothest" driver I know ! Is it going to improve ? Or what am I missing ?
 
It's possibly just the mix of driving conditions - I don't do many really short journeys, though I have covered the full spectrum from town through to high speed motorway.
 
Right, arrived home with 1 x new Cod. Average mpg over 203 miles with mainly motorway but about 50miles of a and B roads is 49.6mpg and creeping up.

I am v pleased with this, seeing as it hasn't done many miles yet.

Absolutely loving it so far, coming from an 04 focus, my modestly specced a3 feels like a different world.

One comment I do have is that whereas the sport suspension is, for me, the perfect compromise between ride and sure footedness, the 17inch tyres do seem to transmit more noise than the se spec wheels I've tried previously, not annoyingly so, just noticable. Do I care? Nope.
 
After spending sometime with our CoD - its giving us 48.5 mpg on mixed motorway driving. Driving across London though was 32 mpg - I think I only managed 4th gear twice!

Its still quite new so I'm sure these will improve as the engine loosens up
 
BigD - is there any markings on your COD to distinguish it as a cod, perhaps on the engine. I can't find anything and it doesn't seem to say much in the manual!