50mpg from 1.4TDI90 on long trip - normal?

timmus

A2OC Donor
Tom do you use some kind of measure and decant the oil into that and carry it around with you?
I do indeed. My car has the 34-litre tank, so I carry 2-stroke oil in 200ml plastic bottles that I bought from an eBay seller many, many years ago. I have ten of the bottles, and usually keep 5 of them in the car at a time. These are cycled with the other 5 in my workshop.
For the 42-litre tank, 250ml bottles would be appropriate.

Cheers,

Tom
 

dj_efk

A2OC Donor
I do indeed. My car has the 34-litre tank, so I carry 2-stroke oil in 200ml plastic bottles that I bought from an eBay seller many, many years ago. I have ten of the bottles, and usually keep 5 of them in the car at a time. These are cycled with the other 5 in my workshop.
For the 42-litre tank, 250ml bottles would be appropriate.

Cheers,

Tom
Thanks Tom - for the purpose of swerving back on to topic - could you summarise your recollection of the fuel economy improvement (as well as other impacts) you noticed?
 

donp38

Member
I will be doing another 500mile run on Saturday.
This time increasing tyre pressures to 40 all around as will be fully loaded..
 

terrywindy1

Member
I did a trip to Burnham on Sea and back on Monday and thought I would see what MPG I could get on a one off round trip the traffic was very heavy both ways but mainly around 60 mph and weather was perfect,205 50 16 Dunlop blue response at 35psi 6 speed box and all 3L aero mods.Stopped in Burnham for about 3 hours so 2 starts from cold I think it's good way too make sure everything is running fine
 

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A2Z

A2OC Donor
I did a trip to Burnham on Sea and back on Monday and thought I would see what MPG I could get on a one off round trip the traffic was very heavy both ways but mainly around 60 mph and weather was perfect,205 50 16 Dunlop blue response at 35psi 6 speed box and all 3L aero mods.Stopped in Burnham for about 3 hours so 2 starts from cold I think it's good way too make sure everything is running fine
Hope it was to play golf at Burnham and Berrow GC? One of my favourite courses although I can't believe I'm saying it but I haven't played there for 31 years.....gosh where did all those years go?😳

That's excellent mpg and 60mph is the key there I think (although your tyres and aero mods will obviously also help) but the difference between 60 and 70mph in an A2 tdi fuel economy wise is huge, probably 10mpg or maybe more πŸ‘
 

jonjo

New Member
Hope it was to play golf at Burnham and Berrow GC? One of my favourite courses although I can't believe I'm saying it but I haven't played there for 31 years.....gosh where did all those years go?😳

That's excellent mpg and 60mph is the key there I think (although your tyres and aero mods will obviously also help) but the difference between 60 and 70mph in an A2 tdi fuel economy wise is huge, probably 10mpg or maybe more πŸ‘
Also the 6 speed box will help with the higher speed/mpg.
I'm jealous of that MPG, I can get 52 if I try hard. New timing belt due soon so I might request a tweak - any updates/news on that "mod"?
 

PlasticMac

Member
I will be doing another 500mile run on Saturday.
This time increasing tyre pressures to 40 all around as will be fully loaded..
You do need to be careful with high pressures. If you over inflate the tyre, the contact patch is reduced, with only the centre of the tread on the road. This reduces grip, obviously, leads to uneven wear, and can cause overheating.
Take a careful look at the patch area.

OK higher pressure can save a smidgen of fuel, but weighed against not being able to stop, or losing control at speed, not worth the risk, imo.
Mac.
 

Proghound

Admin Team
So what MPG did you get and how exactly did you measure it?

The third attachment on that post show the DIS average value at 68.1mpg. Assuming start/finish in Dursley as per profile location, the round trip is about 100 miles. A much longer round trip and careful brimming before and after (to minimise differences between fills) would be required to get a statistically valid proper calculated value. But it's certainly an indication that the FSI is very economical at 60mph. that's in the order of what I might expect to see on the DIS on one of my TDI75s when sitting at 60 on cruise for 100 miles.

EDIT: I realise now that Terry's post is talking about his '90 not his FSI πŸ€¦β€β™‚οΈ doh
 
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A2Z

A2OC Donor
The third attachment on that post show the DIS average value at 68.1mpg. Assuming start/finish in Dursley as per profile location, the round trip is about 100 miles. A much longer round trip and careful brimming before and after (to minimise differences between fills) would be required to get a statistically valid proper calculated value. But it's certainly an indication that the FSI is very economical at 60mph. that's in the order of what I might expect to see on the DIS on one of my TDI75s when sitting at 60 on cruise for 100 miles.
FSI? 😳 I thought this was a TDI 90?
 

PlasticMac

Member
The third attachment on that post show the DIS average value at 68.1mpg. Assuming start/finish in Dursley as per profile location, the round trip is about 100 miles. A much longer round trip and careful brimming before and after (to minimise differences between fills) would be required to get a statistically valid proper calculated value. But it's certainly an indication that the FSI is very economical at 60mph. that's in the order of what I might expect to see on the DIS on one of my TDI75s when sitting at 60 on cruise for 100 miles.
At 60 mph, I think the FSI will still be in stratified mode, just under the changeover at around 2850 rpm.
At 70 mph (ish), we get around 55 mpg. This is all DIS data, but the spreadsheet that I've run since we've had it (2 years) supports the DIS as being accurate.
As @mrbroons said recently, FSIs are fast and frugal.
Mac.
FSI? 😳 I thought this was a TDI 90?
See the FSI is very economical at 60mph. that's in the order of what I might expect to see on the DIS on one of my TDI75s when sitting at 60 on cruise for 100 miles.
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FSI? 😳 I thought this was a TDI 90?
@Proghound says:
"the FSI is very economical at 60mph. that's in the order of what I might expect to see on the DIS on one of my TDI75s when sitting at 60 on cruise for 100 miles"
That's what the reply refers to.
Mac in
 

Proghound

Admin Team
Sorry, I was quite forgetting that @terrywindy1 has a '90 as well as that gorgeous FSI I saw at the social the other weekend :oops:
Not such a surprise if a lightly-driven '90 can roughly match a TDI75 for economy.
 

dj_efk

A2OC Donor
I’ve just realised that Audrey has no oil filler cap so @Clackers has sent one my way - I wonder if the the crankcase not being sealed into it’s closed loop would adversely affect economy? We will see.

My conclusion to everything raised in this thread is that once basic maintenance has been attended to, a VCDS scan is needed to check the 2x coolant temp sensors, thermostat and especially the injection timing / torsion values. A TDI 90 shouldn’t be much less economical than a 75, although many are.
 

donp38

Member
Two long runs done this weekend.
1. tyres at 40psi, AC in eco mode.
limited speed to 70mph.
returned 73mpg (this is at the same pump 1st click.
2. tyres at 40psi, AC on for 1/2 journey (hot afternoon), 1/2 eco mode (late evening cooler)
1/2 journey limited to 70mph
1/2 journey running hard....
65mpg.

Amazing car....nearly 1000miles over two days..
 
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dj_efk

A2OC Donor
Two long runs done this weekend.
1. tyres at 40psi, AC in eco mode.
limited speed to 70mph.
returned 73mpg (this is at the same pump 1st click.
2. tyres at 40psi, AC on for 1/2 journey (hot afternoon), 1/2 eco mode (late evening cooler)
1/2 journey limited to 70mpg
1/2 journey running hard....
65mpg.

Amazing car....nearly 1000miles over two days..
I take it this was achieved with the TDI 75 listed in your profile?
 
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