Most economical diesel for higher motorway speeds

[Another Newbie]

Hello all.

I'm looking to replace my trusty Fabia 1.9TDi, and have been absorbing the helpful info on this forum.

Whittled it down to either a 1.2 TDi Greenline II or one of the two more powerful 1.6 TDi CR engines.

I now have a very specific question:

What will give the best economy at faster motorway speeds?

I'm thinking along these lines:

• I've had the luxury of a powerful car, but it's probably wasted on me.
  

• I realise neither model will live up to the official mpg, but the real world Greenline seems to be about 10% more fuel economical than the 1.6.
  

• Most of my time will be motorway driving and I know I won't have the patience to sit at 65mph, especially on trips of 300 - 400 miles in a day.
  

• I understand that above 65mph economy falls off rapidly in any car, but will this be more marked in the Greenline than the bigger engine?
  

I do 20k (motorway) miles / year.

They all seem to be priced about the same, so what should I do?

Many thanks for your help.

[greenline 11]

Better view my threads before you give up your car. Owned a Greenline diesel for 18 months, similar mileage to your own as in annum, and couldn't get more than 50 mpg. Got shut and now own a Kia Rio doing 60+ to the gallon and climbing by the day ... caveat emptor!

[BossFox]

I did 20k miles in a year in my Fabia GL2, but I did stick to 62mph and saw an average of 72mpg real (not maxi-dot) over the whole 20k miles.

Personally if you want to be doing 70-80mph most of the time I'd pay the extra £10 per week in diesel and go for a 105bhp 1.6 TDi CR.

[logiclee]

The Fabia is a tall bluff fronted supermini, high speed really hurts economy.

At 80mph my 2.0tdi DSG Passat was more economical than our old 1.9TDi Fabia. From what I've read the 1.6TDi CR struggles to match the old PD unit, can't imagine the 1.2tdi is great at 70+. Economy really dips at 70+ on our 1.2tsi too.

Drag cd .33 for the Fabia, .27 for the Passat.

Might be better with a bigger saloon for high speed motorway work even if it means going a year or two older.

Cheers

Lee

[arny]

My 1.6 tdi 105 Fabia gets 60mpg on my A road commute doing 50mph most of the way. Motorway driving reduces it to low 50's mpg . Driving company pool car Octavia 2.0 Tdi's i can achieve 60mpg on motorway runs without trying.

[bluecar1]

the GL II is very capable on the motorway, daughter has a monte 1.6tdi 105ps

long run at 60-65 mph GL does mid 70's and monte does mid 50's, 70-75mph the monte drops to 50ish and the GL down into mid 60's

[logiclee]

65mpg @ 75mph from a Fabia?

I'd be highly suprised if those figures are accurate.

Cheers

Lee

[logiclee]

My 1.6 tdi 105 Fabia gets 60mpg on my A road commute doing 50mph most of the way. Motorway driving reduces it to low 50's mpg . Driving company pool car Octavia 2.0 Tdi's i can achieve 60mpg on motorway runs without trying.

Pretty much my findings and the quicker you go the wider the difference.

What Car found the 2.0tdi cr engine more economical than the 1.6tdi for motorway use in many vag models.

Cheers

Lee

Edited 19 April, 2013 by logiclee

[BossFox]

65mpg @ 75mph from a Fabia?

I'd be highly suprised if those figures are accurate.

Cheers

Lee

I did one test tank in my GL2 when I drove it like an absolute loony, so I could compare with my best result of 78mpg(real, not display).

Pulling away fast and frequent visits to 80 leptons. Still got an average over the tank of 61mpg. (real)

Not sure if it makes a difference, but I had the more streamlined estate.

Only thing I didn't really do with the car was sit in lots of traffic, it was for commuting.

[Another Newbie]

Thank you all for your input. It's really useful to have some figures to work with.

Lee - interesting about the aerodynamics. I hadn't thought about that side of it but I see that's going to become more important at speed.

And thanks also to you folks whohave given your GLs a bit of a hard time.

Will look at Octavias and book a test drive or two.

[full_throttle]

how fast do you want to drive. I had to drive from central Birmingham to Coventry the other week, doing a steady 65mph I averaged 63mpg according to the maxidot computer, and that includes a stop at tesco on the way home.

[Another Newbie]

Hi Full Throttle,

Was thinking of steady 70-75 with the possibility of 80 occasionally.

This would be about half the mileage, say, 10k. I'd underestimated how much A-road driving I do on my original post - my work can be pretty variable in where it takes me.

So having thought about the figures people are posting I'm leaning more towards a Fabia Greenline, if people think it will take it!

Edited 20 April, 2013 by Another Newbie

[BossFox]

A GL2 will sit at 90mph if you want too.

You just lose the best feature, it's economy.

But then most cars lose economy the quicker you go.

[Another Newbie]

That's massively helpful Bossfox.

Can't see myself doing that sort of speed but it's reassuring to know that it's not going to be thrashed if I suddenly lose the will to be economical.

Best of both worlds?: Economical if you want it but can cope with fast long journeys if you just want to get there.

[BossFox]

Best of both worlds?: Economical if you want it but can cope with fast long journeys if you just want to get there.

Well, what the GL2 lacks is flexibility.

It has spaced out gears (it will actually cruise at 100mph quite hapily on the flat) and lower power than the 1.6 CR (unless you get the lowest power version of the latter) which means that the GL2 has one area it falls down on. Overtaking/building speed.

If you want to go past a car doing 68mph you may have to wait a bit longer for a gap and you may need to have your foot right down for a while to build the momentum up before attempting the manouver.

That's the downside to the extra economy.

[Another Newbie]

That's a compromise I'm very happy with.

A look at the mpg people seem to be getting seems to show about 20 percent better economy both at 60 ish or at 75-80. Think I'll save £600 per year - more if I can be patient :-)

Edited 22 April, 2013 by Another Newbie

[Igloo Vindaloo]

I find my Greenline II estate to be very good on the motorway, except:

• If fully loaded don't try to pull out to overtake slow trucks on steep hills in 5th - you really have to work the gears like a petrol.
  
• The fuel consumption climbs startling at high speed. On a warm summer day on a flat road with just me, I got the following:
  
  • 95MPG @ 56mph,
    
  • 88MPG @ 62mph,
    
  • 83MPG @ 68mph,
    
  • 67MPG @ 75mph.
    

  [*](Each measured from the computer over 20km over driving with cruise control with no more than 20m change in height, 25C, average speed from GPS (or trip computer average, not speedo or set point, which is 5km/h higher).

As mentioned, the Fabia has the aerodynamics of a streamlined brick. I would love to do a similar experiment with the same engine etc in the Seat Ibiza Ecomotive...

Edited 22 April, 2013 by Igloo Vindaloo

[full_throttle]

A.N. my wifes Monte Carlo has touched a ton without any trouble, still less than 3.5k revs, obviously fuel consumption is lower.

I can drive it at 80 most of the way down the motorway and still get near on 50mpg. I'm getting old now (46) so speed isn't important to me anymore, I'd rather get there safely

[Matt Pez]

I have had a 1.2 TDi Fabia on loan in the past and also a Roomster with what I think was the same engine and both struggled to get over 50mpg on the maxidot on a run up the A1 to York or down to Notts and back. My 170CR Berb always seems to average 52mpg on the maxidot over a tank of fuel and can show 60mpg on warm days with minimal traffic. I tend to cruise at 70-75mph. I expect the 150CR Octavia to average 60mpg based on my style of driving and mix of journeys. I would always choose a 2.0 over a 1.6 in a larger car so would suggest the 1.6 Fabia would be better than the 1.2 for motorway cruising. Might also be worth considering a low/mid spec Octy with the larger unit if you are covering 20k per year, the larger class of car comes with more toys/better comfort on entry spec cars compared to Fabia so might not be as much of a step up in price than you may first think?

Edited 22 April, 2013 by Matt Pez

[Carlodiesel]

Interesting................

http://www.confused.com/car-insurance/articles/dont-be-mislead-on-mpg?MediaCode=806&utm_medium=email&utm_campaign=Newsletter&utm_source=Newsletter22April

[caradoc]

Did a run from Herefordshire to Norfolk and back (included some rural roads) and achieved 64mpg according to the computer (105hp). Understand there are lots of discrepancies on mpg figures but compared to the dismal 33mpg from the Fabia vRS it replaced we're delighted!

[Another Newbie]

Thank you all very much indeed for your input.

It sounds like, apart from early teething problems and one particular dud (@greenline ii - I did have a good look at your thread and really feel for you on that one), people are generally getting really good mileage out of both engines, so it's just a case of deciding if I can put up with lower flexibility of the Greenline.

If I can get anything close to BossFox and Igloo Vindaloo's mpg I'll be very, very happy.

I also looked at Octavias as a couple of people suggested. If I was going second-hand I'd absolutely take that advice, but I can't resist the current 25% off new Fabias.

So.....Test-drive booked for a Greenline Estate tomorrow :-)

[Carlodiesel]

Dont forget to test the Diesel while your there and compare the two.

We did that & went for the Diesel.

It won hands down.

[Web Ferret]

I too am after the holy grail commuter to sit in 60 miles/2 hours a day.

60+ mpg at 70mph with the beans to overtake on a motorway uphill or get past a muppet. Also the ability to make up lost time and still get 50+ mpg.

My PD2.0 is good but given diesel is only going one way faster than wages, my next car will need the specs above!

5 years ago diesel was £1 a litre so the 2.0TDI PD was ideal.

Edited 23 April, 2013 by Web Ferret

[Guest BigJase88]

Its strange this predicament

My tdi 150 1.9 leon got 40mpg at 90mph fully laden

My mates a5 240bhp 3.0l tdi got 42mpg at 90mph following me

I was dumbstruck!

If your horsing on the bigger displacement is more economical doesn't struggle as much you see