Worth paying a premium for a diesel engine?

Chat Forum

[closed]

Worth paying a premium for a diesel engine?

129 posts & 46 voices | Started 2 years ago by thisisnotaspoon | Latest reply from molgrips

Tags:

No tags yet.

Pages: « Previous 1…34

robdob - Member

In my experience the "incresed fuel economy" is mostly a myth. In my new job I have had a LOT of hire cars in the last year, all newish, whilst at the same time running my 2001 1.6vvti Corolla 110bhp (petrol).
I have 18 months of very accurate fuel consumption data for my Corolla (every bit of fuel in, every mile accounted for).
I have driven the same in every car (watching the instant MPG reading to see how mpg can improve, but occasionally having fun or overtaking when I want to).
My Corolla got 39mpg AVERAGE, with figures ranging from 32 to 49mpg (32 a tank ALL around town, 49 on a trip 4 up, fully loaded 1000 miles to Cornwall).
My current car, Kia Cee'd 1.6hdi EcoDynamic (with stop start modern engine, and quoted 55mpg - 65 mpg) is currently 45mpg.

6mpg difference. Oh WOW - I'll be a millionaire!

I've not had a turbo diesel engine leased to me yet that can average more than 47mpg - and remember this is with IDENTICAL driving using each car at its most economical.

I had a Vauxhall Insignia SRi 1.9cdti estate (auto admittedly) and on a long relaxed trip to the cotswolds and back did 36mpg.

So don't argue the fuel consumption myth with me, I'm sorry it just isn't true, the only increase is swallowed up massively by the extra cost in the first place.

I am getting an Astra 1.7cdti EcoFlex as a permanent comapny car soon.

My Corolla will be sorely missed.

Posted 2 years ago #
lakesrider - Member

must depend where you drive ie lots of traffic etc?

I have a 2.0 TDI which gets me average 54mpg, but the petrol car i drive, a 1.4 vtec thing that i dont rev the nuts off only gives me about 42mpg. (both in fairly traffic free rural areas which is most of my driving) Of course the computers could be lying to me!

Posted 2 years ago #
robdob - Member

My results aren't on what the trip computer says, I log all the petrol purchases and odometer readings and enter them into an iPhone app I have. Tank brimmed every time..

Mind you, I do reset the trip computer every time and I find that every car has been within 2-3mpg of what I've calculated each time at the very most.

Posted 2 years ago #
molgrips - Member

You seem to be contradicting yourself so I wont say any more

No what I'm saying is for performance, compare like with like. As in, a petrol sports car will clearly be more powerful than a normal family diesel...

So don't argue the fuel consumption myth with me, I'm sorry it just isn't true, the only increase is swallowed up massively by the extra cost in the first place

I'll argue with that, as would most people. Did you know for example that in wintertime they sell diesel that has anti gelling agents in it that reduce fuel economy? Your Kia would be significantly more efficient in the summertime, about 5mpg or more. And your Vauxhall must've had something wrong with it for sure. 36mpg from any of my diesels and they'd have been straight back to the garage. Ridiculous.

My Seat Ibiza got 57mpg in the summer and 53mpg in the winter. Care to explain that if it's such a stupid myth? Your Kia is either rubbish, you don't know how to drive or there's something wrong with it. Oh and petrol pumps aren't that reliable, they vary the point at which they stop filling hugely from pump to pump. It is very much not definitive.

My Passat (comparable to your Insignia) gets 48mpg in the winter and low 50s in the summer although I only did a couple of trips on summer diesel. I'd be seeing 35 or so from a petrol I imagine.

To be honest mate saying that diesel drivers are all stupid and wrong based on your couple of cars is a bit offensive. You should've said something like 'I've not really seen much difference in fuel economy, not sure what's happening there' instead of calling us all wrong and gullible.

Posted 2 years ago #
willard - Member

Well, people are posting lots of pictures, so I thought I would post up chart of the calculated economy figures I maintained over 121 or so tanks of fuel on my Rover 620 SLDi (I know, shit car).

The first set of results are from when I was driving 70 miles each way to work and back on a dual carriageway. A tank lasted me roughly four days. You can also see the drop to lower economy when I moved house closer to work, leaving me with a drive through town and along a single carriageway A road.

There is no way a petrol would have got me the sort of economy the shitty Rover did on the long commute, but a cheap petrol would have done when I moved house.

Posted 2 years ago #
anagallis_arvensis - Member

How was the Kia? Attracted by the long warrenty.

Posted 2 years ago #
robdob - Member

To be honest mate saying that diesel drivers are all stupid and wrong based

When did I say that? Please read my post properly before you accuse me.

on your couple of cars is a bit offensive.

Its actually 11 different cars, over about 20,000 miles in total. 3 petrol, 8 diesel.

And your Vauxhall must've had something wrong with it for sure

Might have, I don't know. I did say it was the SRi, and an auto box, which might explain that..?

I'd be seeing 35 or so from a petrol I imagine

So you don't actually know at all then? You're just guessing based on no experience, and you argue that I'm wrong? Strange logic...

Your Kia is either rubbish

I will admit that is very possible!
However, it is exactly the sort of car that the ill-informed masses are ditching their perfectly good petrol cars to buy.

Posted 2 years ago #
Harmitans - Member

I am comparing like for like though. Take the VW passat as an example, some of the engine options available are 2.0 Petrol, 2.0T Petrol, 3.2 Petrol and 2.0TDI. So the car is the same only the engine is different.

The 3.0 Petrol I refer to is a BMW 330 4 door saloon, I don't see this as a sports car. For the same price and same age I could have an Audi A4 2.0TDI, a car that I consider to be in the same class.

If I did huge mileage I may consider a Diesel but in my opinion the only plus point they have is fuel economy. I prefer everything else about the petrol engine.

Posted 2 years ago #
robdob - Member

How was the Kia? Attracted by the long warrenty

Looks ok (if you don't have very high standards). Nice to sit in and drive, seems good quality inside too for the money. Loads of storage bins etc which make it very useful. However the 1.6hdi engine sounds dog rough (compared to Honda/Vauxhall/VAG, well pretty much everything) and performance is woeful.

It was a surprise when I got in it how good it was tbh, but I drove a new Astra at Millbrook at an invitation only event and it was better in every way than any other car in its class. I preferred it to the A3, Golf, Civic, Focus etc etc which I tested side by side there. Really good engines, handle well, exceptional quality. If I had a choice I'd have a new Astra in a heartbeat.

Posted 2 years ago #
robdob - Member

but in my opinion the only plus point they have is fuel economy

... and if you consider the overall cost of a car (which surely you should be doing if you care about mpg as it's all about the money at the end of the day) then they even have that point unless you are doing monster mileage!

Posted 2 years ago #
Harmitans - Member

Exactly Rob! It's about choosing a car to suit your needs.

My family told me I should have bought a diesel when I bought the BMW and I explained with figures why they were wrong and they just don't get it. The same people also say how nice my car is to drive!

Posted 2 years ago #
robdob - Member

they just don't get it

I think it's the diesel fumes that have addled some peoples brains....

Posted 2 years ago #
tonyg2003 - Member

Just been looking at this on purely financial grounds (hopefully more subjective). Since am seriously thinking of changing cars.

2009 Passat 170bhp DSG TDI vs 2.0T DSG. Cost difference is ~£3000.

Driving 10000miles per annum (combined 33 petrol vs 46 diesel - seems about right) you would have to drive ~60000 miles to breakeven. Not so bad for a 20K pa driver like myself but for you average 10-12k pa driver it's harder to justify.

Doesn't take into account everything such as residuals, insurance or servicing costs, future differences in fuel etc... but not exactly clear cut no matter which way you look at it.

Residual values of different cars would seem to be more important financially than fuel costs.

Posted 2 years ago #
owenfackrell - Member

If you want to see turbo lag then top gear did a test of the EVO FQ400 againts a fiat diesel car both had to accelerate from 30 mph in 5th the fiat left the Evo for dead and it only just caught up when they got to the end of the straight.

Having until recently owned a 1.9 dci and a 2.0 petrol i can say that as mine wasn't a VW engine, they are know for the lumpy way the deliver power, that the turbo started to wind up at 1200rpm and felt smooth with very little turbo lag where as the petrol just doesn't wind up the smae way until you hit 2500rpm+. For fast driving i would pick th epetrol every day but for relaxed city/motorway driving i would have a diesel for its lazy nature as well as the better fuel economy. The best i have seen in the petrol is 40mpg verse 55 in the diesel and that car wieghed over half a tonne heavier.

Posted 2 years ago #
mastiles_fanylion - Member

If you want to see turbo lag then top gear did a test of the EVO FQ400 againts a fiat diesel car both had to accelerate from 30 mph in 5th the fiat left the Evo for dead and it only just caught up when they got to the end of the straight.

So much has been said in this thread about gearing yet you bring that up! Try the same test if both cars can start in the most appropriate gear.

Posted 2 years ago #
Harmitans - Member

The FQ400 example is not turbo lag either, it's due to the engine being below the boost threshold and being unable to spool the turbo.

Posted 2 years ago #
mastiles_fanylion - Member

The FQ400 example is not turbo lag either, it's due to the engine being below the boost threshold and being unable to spool the turbo.

Very good point.

Posted 2 years ago #
molgrips - Member

When did I say that? Please read my post properly before you accuse me.

You said diesel fuel economy was a myth. What I took that to mean was that we are all somehow deluded in thinking diesels are more economical - ie we think they are and they are not, which in turn is like saying we are wrong.

Its actually 11 different cars, over about 20,000 miles in total. 3 petrol, 8 diesel.

And how many cars are on the market?

So you don't actually know at all then? You're just guessing based on no experience, and you argue that I'm wrong? Strange logic...

Well I have owned and driven petrol cars, and so have my mates. I've just never driven a new model petrol Passat which is why I said 'imagine'. I used to own an old one which got 38mpg on only gentle long country drives, no town driving. Published figures for Passats are either 42mpg or 38mpg depending on which power option you go for, and that's the very impressive TSI engine which as I've said before is very possibly a rival to the diesels in the Passat, particularly in terms of emissions. However I don't think this level of technology is widespread yet.

As for a 3.0L petrol being a like for like comparison with a 2.0 TDI, again I don't agree. Fuel costs, insurance and tax must mean it's a more expenisve premium option, surely? What fuel economy do you get in real life?

i can say that as mine wasn't a VW engine, they are know for the lumpy way the deliver power

Not any more mate. That was the old VW diesels, new ones are much better.

I just checked the VW price list - a 1.4 TSi 122hp Passat is £1,100 cheaper than the 110hp TDi, and does 9mpg fewer - 42 vs 51. So about 4 years payback ish based on 12k miles a year. VED savings are £25/year. On the other hand, the Bluemotion version is available at 63mpg and £1700 premium over the 1.4 TSi, which would pay back in 3.5 years ish for fuel - but the VED is £120 per year LESS than the petrol.

Bear in mind this is the one of the most efficient petrol engines out there.. I must say I am actually quite interested in it as an alternative to diesel because of its lower emissions and even power delivery. But as for standard NA petrols - no chance.

And let's not forget, cost is not the only factor here.

Posted 2 years ago #
lakesrider - Member

regarding the VAG TSI petrol engines, on paper they have good eonomy, but the one i drove for a few hours i found i had to drive it very 'careully' to get the published figures, unlike diesels where i just tend to drive relative to the conditions and trafic and it gives very good mpg.

I've also had a few VAG car dealers telling me that the economy on the TSI isn't as good in real life. Now this could be because they are new engines and a lot of them havent 'run in' so ecomony will improve, or could need some tweaks to the ECU on them as they are new technology.

Posted 2 years ago #
owenfackrell - Member

i can say that as mine wasn't a VW engine, they are know for the lumpy way the deliver power

Not any more mate. That was the old VW diesels, new ones are much better.

It was the older 1.9 i ment.

The whole point of hte FQ item was to show how poor the car was off boost as it had been total desgined around the turbo.

Harmitans - Member
The FQ400 example is not turbo lag either, it's due to the engine being below the boost threshold and being unable to spool the turbo.

Isn't that what turbo lag is? ie waiting for the turbo which is laging behind the engine. It can happen when you change gear and drop out of the turbo range or if you are off boost.

Posted 2 years ago #
Harmitans - Member

There is a difference. Below the boost threshold the turbo will not spool however long you wait. Above the threshold the time between opening the throttle and the turbo generating boost pressue is the lag time.

If the engine produces enough torque below the boost threshold then the car will accelerate slowly until it reaches the boost threshold, the turbo will then spool and the car will accelerate faster. All the FQ400 example shows is an engine that doesn't have much torque below the boost threshold and a reasonably high boost threshold.

Posted 2 years ago #
robdob - Member

"And how many cars are on the market?"

So do I have to drive every single car on the market to make my argument valid. It's at least better then your comment:

"I've just never driven a new model petrol Passat which is why I said 'imagine'. I used to own an old one "

Ahhh, a direct comparison like I've been able to do?
No.

"And let's not forget, cost is not the only factor here."

Yes I know, diesels drive like crap. If I could choose the car I have I'd go for petrol because:

a) I have learnt how to change gear at an appropriate time (do the diesel advocates really think having to move your hand and press your foot down really stressful?). If you really can't be bothered to change down a gear then I hope you can be bothered to brake!!
b) I like to drive - I don't just have it as a "tool" - Q. - are the bikes you choose the most efficient for how you ride? Don't get me started about singlespeeds!
c) I can tell the difference between different handling cars.
d) I can do maths.

Posted 2 years ago #
TheLittlestHobo - Member

Who cares. If you want a diesel buy a diesel. If you want a petrol buy a petrol.

I run a diesel for work and look forward to driving my wifes petrol polo at the weekends. I have driven more miles in diesel VW's than i car to remember. The end result, its a diesel, end of.

I sell commercial vehicles for a living and diesel rules, but really, for joe bloggs who drives 15k per annum there isnt really a defining argument for or against either engine.

Lets discuss the merits of bigger brakes on your bikes, its a similar ever decreasing circles type argument which gets tedious

Posted 2 years ago #
molgrips - Member

Robdob, am I wrong about the Passats? Are the diesels more efficient than the petrols? Yes. No-one apart from you argues this. I showed you some figures which showed that the payback time in terms of money is 40-50 thousand miles, which is what everyone else has been saying all along. So what's your point?

You seem to be making up loads of strange arguments and I am not quite sure why. You are allowed to prefer petrol, that's ok - just don't say wrong things about them not being efficient. That's what I was trying to call you on, really. How else do you explain the 57mpg Seat Ibiza or the 65mpg Bluemotion Passat?

About changing gear - it's effort. Small, but it's there. Otherwise why did people invent automatic gearboxes? Again, you are allowed to enjoy changing gear, as I would if I were faced with a windy mountain road, but again on a motorway it's a different game. I know how to do it, and I am a fine driver from a technical point of view.

Out of interest, why did you bother typing that stupid stuff about me not bothering to brake? Was it really worth it?

Posted 2 years ago #

RSS feed for this topic

Pages: « Previous 1…34

Topic Closed

This topic has been closed to new replies.

Singletrack Mountain Bike Magazine

Chat Forum

Worth paying a premium for a diesel engine?

Topic Closed

Don't miss…

Singletrack

Website & Forums

Exits