Author Topic: 18" vs 19" GTD MPG  (Read 6508 times)

Offline Sootchucker

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18" vs 19" GTD MPG
« on: 27 February 2017, 13:15 »
Just a musing guys, but was entering another fill up on my fuelly account this morning and noticed the difference in MPG from my old White 2013 GTD (DSG- 18" Negaro's) vs my current 2016 GTD (DSG but with 19" Santiago alloys).

For the white GTD, my average stood at 45.9mpg (63 fill ups over 23,227 miles) vs for my Carbon Grey GTD of 44.4mpg (but only 18 fill ups over 7000 miles). Whilst they are both quite similar (only 1mpg in it), it has got me wondering if the MPG suffers slightly as a result of the larger wheels ? VW's brochure doesn't say anything about 19" alloys (even for the Co2 ratings).

Now I know I did many more miles in the first car over a longer time, and a lot of my current car's MPG has been done from Oct to present (so colder days), it got me wondering if there is any fuel penalty for using the 19" alloys vs the stock 18" units. They both have 225 section tyres, and the above is hardy scientific, but it peeked my curiosity.

It's totally unimportant to me (even if they are worse) as I love the look of the Santiago's, it was just a question that popped in my head ? 
« Last Edit: 27 February 2017, 13:17 by Sootchucker »
2022 Tiguan R-Line 2.0 TSI 4-Motion. Nightshade blue, pano roof, IQ lights, Nav Pro, Harmon Kardon, Heated Windscreen, Heated rear seats, Wireless charging, Heads up display, dual height boot floor, Keyless with electric tailgate, Electronic TPMS, underbody protection, Area View Cameras

Offline brettblade

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Re: 18" vs 19" GTD MPG
« Reply #1 on: 27 February 2017, 13:48 »
I think it's probably not a fair comparison until you've had the equivalent summer driving, and are the tyres like for like?

On a side note, your real world MPG in the GTD makes me feel more comfortable with the MPG in my GTI!
Orded 04/06/2016
Build W/C 01/08/2016
Handover 01/09/2016
GTI PP, CSG, Tech pack, parking pack, 90% tints, DCC, 19" Santiago alloys
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7.5R Indium Grey, 19” Spielbergs expected 01/03/2019.

Offline Sootchucker

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Re: 18" vs 19" GTD MPG
« Reply #2 on: 27 February 2017, 15:02 »
Thanks bud, why what are you getting out of the GTI ?

A point to note is that on both cars at least 70% of the mileage is urban to work and back though a major town center with lots of lights etc. so in fairness I don't think @45mpg is too bad. On both cars I've head very high fifties (57-59mpg) on many occasions when taken on a longer run, and on one occasion in June last year (much warmer @ 20°C) in the newer car nearly 64mpg (my trip computer is about 1mpg optimistic) so around 62.5-63mpg real.

2022 Tiguan R-Line 2.0 TSI 4-Motion. Nightshade blue, pano roof, IQ lights, Nav Pro, Harmon Kardon, Heated Windscreen, Heated rear seats, Wireless charging, Heads up display, dual height boot floor, Keyless with electric tailgate, Electronic TPMS, underbody protection, Area View Cameras

Offline brettblade

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Re: 18" vs 19" GTD MPG
« Reply #3 on: 27 February 2017, 15:06 »
I'm getting about 34 MPG long term average, it's lower than I was hoping for but not disastrous.  I was getting c48 MPG out of a PD130 Ibiza doing the same journeys.
Orded 04/06/2016
Build W/C 01/08/2016
Handover 01/09/2016
GTI PP, CSG, Tech pack, parking pack, 90% tints, DCC, 19" Santiago alloys
Soon to be gone!

7.5R Indium Grey, 19” Spielbergs expected 01/03/2019.

Offline fredgroves

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Re: 18" vs 19" GTD MPG
« Reply #4 on: 27 February 2017, 15:13 »
The 19's definitely effect the CO2 figure, but for some reason its never quoted.

Usually thats because of extra weight.

Hard to get a scientific reading, but quite probably the variance you are seeing there is correct.

Also, have a look at the official CO2 figure for your current car (check with the DVLA) and see what your old one was... I suspect that your old one was less than your current one.

There is definitely something fishy going on with VW and GTD's....
Current: Mk8 GTI DSG, Adelaides, DCC, HUD, HK, Winter Pack, Rear Camera.. Aka "HMS Weasel"

Gone: 2017 Mk7.5 GTD,manual, NavPro
Gone: 2014 Mk7 GTD, manual, NavPro, DCC

Online jv

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Re: 18" vs 19" GTD MPG
« Reply #5 on: 27 February 2017, 15:25 »
Do you, the driver, weigh the same as you did 2 or 3 years ago?
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Offline Sootchucker

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Re: 18" vs 19" GTD MPG
« Reply #6 on: 27 February 2017, 15:48 »
Bog off and mind you own business..........cheeky - what are you trying to say jv  :grin: :grin:
2022 Tiguan R-Line 2.0 TSI 4-Motion. Nightshade blue, pano roof, IQ lights, Nav Pro, Harmon Kardon, Heated Windscreen, Heated rear seats, Wireless charging, Heads up display, dual height boot floor, Keyless with electric tailgate, Electronic TPMS, underbody protection, Area View Cameras

Online jv

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Re: 18" vs 19" GTD MPG
« Reply #7 on: 27 February 2017, 15:53 »
Haha :grin:

Just need to add these vital factors into your calculations. What's the difference in wheel weight versus 'driver changes'...  :evil: :grin:
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Offline Sootchucker

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Re: 18" vs 19" GTD MPG
« Reply #8 on: 27 February 2017, 15:57 »
The 19's definitely effect the CO2 figure, but for some reason its never quoted.

Usually thats because of extra weight.

Hard to get a scientific reading, but quite probably the variance you are seeing there is correct.

Also, have a look at the official CO2 figure for your current car (check with the DVLA) and see what your old one was... I suspect that your old one was less than your current one.

There is definitely something fishy going on with VW and GTD's....

You are right. I've just checked from some older catalogues I had and from the DVLA website, and it's showing my 2013 car as Co2 122g/km and my new car 127g/km. However although my new car is shown on the DVLA website as 127g/gm, in the Jan 2017 VW Golf brochure, whilst it quotes also 127g/km, that's for 18" wheels. No mention at all for 19" alloys, so where has the extra 5g/km come from ?
2022 Tiguan R-Line 2.0 TSI 4-Motion. Nightshade blue, pano roof, IQ lights, Nav Pro, Harmon Kardon, Heated Windscreen, Heated rear seats, Wireless charging, Heads up display, dual height boot floor, Keyless with electric tailgate, Electronic TPMS, underbody protection, Area View Cameras

Offline fredgroves

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Re: 18" vs 19" GTD MPG
« Reply #9 on: 27 February 2017, 16:17 »
Have look again and see what the same car is now for a Mk7.5...
Current: Mk8 GTI DSG, Adelaides, DCC, HUD, HK, Winter Pack, Rear Camera.. Aka "HMS Weasel"

Gone: 2017 Mk7.5 GTD,manual, NavPro
Gone: 2014 Mk7 GTD, manual, NavPro, DCC