Octavia TDI MPG VS RANGE - Fuel Economy?

[adz1]

Hi Guys

Ive got a 1.9 TDI 110 Octavia L+K 2002, probably can do with a service but after a full tank it displays 380miles, im quiet curious how accurate is that as many people have stated 400-550 miles displaying. Also my MPG is showing 28.2MPG local, if i drive sensible id get 40MPG.

This all doesnt add up does it? Surely i thought id get 40+MPG on a 55litre tank (im assuming its that big) id have thought of 450-600 miles depending on conditions etc. Although its been a scorcher last few days and i just fuelled up full yesterday was pretty gutted with the range showing only that much.

[KenONeill]

I can get my mpg that low, by only doing trips under 3 miles.

[pimpdriver]

Are you doing genuine brim to brim refills?

That is the only way to get an accurate reading.

My 2004 90bhp gets 58mpg

[octaviadan]

My 110 Elegance fuel computer is inaccurate - it tends to overread by around 10mpg and after fill up computer states I have around 700 miles of fuel!! Realistically from full to 'light on' I have covered around 470 to 490 miles. The only way is to work it out accurately is from brim to brim fills and by doing the calculations yourself.

For the record my Octavia has averaged exactly 50mpg over records taken on 39 separate brim-to-brim re-fuellings (best being 53.2mpg; worst 46.1mpg), covering approx 400 miles per week with at least 3 to 4 days undertaking a 70 mile round commute, mixture of A roads (mostly 50mph limit) and some city driving.

These engines do seem to vary a lot with fuel consumption and performance - think mine is an 'average' 110 on consumption and performance, despite all turbo issues sorted.

I find that regular routine servicing helps. Always change your air filter at 10k miles (not at the recommended 40k!) that always makes a big difference with performance and economy.

Hope this helps

Dan

[adz1]

Hi Guys thanks for responding

So to update you; just had a full service + Cambelt kit (waterpump) changed. So far ive done 145miles, the computer is displaying at 40.3MPG, ive driven mainly on A roads and have had AC on a few times as its getting hot in UK. My current range is displaying 340Miles left with half a tank of fuel.

It just doesnt make sense to be showing 385miles at full tank and 340miles at half tank after 145miles. I have been driving sensible and odd occassion 20-30miles on motorway but being a 110 it aint going to sprint that quick to suck alot of diesel out.

[pimpdriver]

Just ignore the computer.

Use genuine brim to brim, keep a record in a book using a pen, and work out what you're really getting.

[mac11irl]

Are you doing genuine brim to brim refills?

That is the only way to get an accurate reading.

My 2004 90bhp gets 58mpg

I get an indicated 63mpg, calculated 58mpg from my 90 bhp 1.9tdi. 2004 plate

My method for clculating isnt Brim to brim though...

i reset the odometer trip when the reserve beeps.

tank up with about 45l, not quite brimming, then watch until the beep kicks in again.

u have a similar bottom level, and a known quantity of fuel gone in, and the milage between beeps..

[octaviadan]

Hi Guys thanks for responding

So to update you; just had a full service + Cambelt kit (waterpump) changed. So far ive done 145miles, the computer is displaying at 40.3MPG, ive driven mainly on A roads and have had AC on a few times as its getting hot in UK. My current range is displaying 340Miles left with half a tank of fuel.

It just doesnt make sense to be showing 385miles at full tank and 340miles at half tank after 145miles. I have been driving sensible and odd occassion 20-30miles on motorway but being a 110 it aint going to sprint that quick to suck alot of diesel out.

Do at least a couple of brim-to-brim re-fuels and work it out manually - that will give you the accurate figure. Even if your fuel computer is inaccurate, yours does seem to be using much more diesel than others on the forum. Are you sure you have no other issues? Have you had a code scan on VCDS? Any excessive black smoke when you accellerate hard?

Other items which could cause yours to use more fuel is CTS (Coolant Temperature Sensor) and MAF sensor. When you had the cambelt done, did the garage set the timing up on VCDS? This could also be issue if not set up correctly. Have you any performance issues?

Dan

[adz1]

So far done 165miles half tank gone 290miles range left. I doubt i will get that from half the tank. But will keep you posted what i get.

I will run scan using friends SnapOn Diagnostic. However no MAF issues, acceleration is good no black smoke on acceleration - just got serviced too.

Im not sure how i would check CTS? Will that come up on the diagnostic?

Also the garage i got cambelt changed i doubt they have a VAGCOM machine to put timing back in. Is this fairly easy to do? Is there anyone willing to assit me in this?

No performance issues runs good. Just seems to be guzzling then sipping

[trundlenut]

Look in the VCDS / diagnostics forum for the list of people with VCDS and see if there is someone near you who can check the timing.

They could also check the maf and CTS at the same time.

Sent from my Nexus 4 using Tapatalk 2

[octaviadan]

So far done 165miles half tank gone 290miles range left. I doubt i will get that from half the tank. But will keep you posted what i get.

I will run scan using friends SnapOn Diagnostic. However no MAF issues, acceleration is good no black smoke on acceleration - just got serviced too.

Im not sure how i would check CTS? Will that come up on the diagnostic?

Also the garage i got cambelt changed i doubt they have a VAGCOM machine to put timing back in. Is this fairly easy to do? Is there anyone willing to assit me in this?

No performance issues runs good. Just seems to be guzzling then sipping

At half a tank, I am usually about 270-280 miles so really is using far more fuel than it should.... Once you have found someone local to do a VCDS scan, I would also do some runs to test the MAF using the measuring blocks (can't remember which group it is though - someone will confirm!).

CTS is a common issue - is yours still the original black one or the upgraded green one?

[adz1]

Not sure which sensor is in the car or if it has ever been replaced. If the CTS measures the engine temp then its bang on 90 quick as its warm weather here.

Ive messaged a few people for VCSD and if they know how to adjust timing to holla at me so lets see who gets back hopefully its not pricey.

Would the CTS cause it to burn more fuel?

Another issue i just realised when i turn on heaters on full blast, the air blows in intervals of high and low. But if i adjust this down it is a constant steady flow. Can this be the fan? If so will this affect my Diesel Octy, that thinks its a Petrol VRS drinking like anything.

[octaviadan]

The CTS has two circuits; one for the instrument readout and one to inform the ECU. They can fail on either, or both, circuits. Mine failed on the ECU circuit as my temperature readout was fine. Fault was picked up by VCDS.

If the CTS sensor has failed, the engine will use more fuel if the reading from the sensor is telling the ECU that the temperature of the coolant is cooler than it actually is and will overfuel.

Not sure what the heater issue is but should be a constant steady flow at whatever temperature. Maybe you have an air lock after the cambelt and waterpump change?

[trundlenut]

The CTS can also go wrong without giving an error (or only occasionally). If it gives the wrong reading but in the right range no error. Its only if it tells the ECU a stupid temperature (say -50) that an error pops up.

Does it ever idle fast?

Sent from my Nexus 4 using Tapatalk 2

[adz1]

Ok as an update

I scanned my car using SnapOn Ethos but that only found one code see pic.

Then i met up with someone who had VCDS and found these results. Please advise guys as i dont know what it all means :(

[adz1]

other pics

[adz1]

sorry guys the forum doesnt allow me to upload any more. But do they make sense.

Measuring Block 015 Test

924/min 2.8Mg/str 0.40l/h 0.0 mg/str

RPM inj.quantity fuel consumption inj quantity

Test03

903 /min 260.0 mg/str 460.0 mg/str 4.8 %

RPM Mass Air/Rev Mass Air/Rev Duty Cycle

Test 01

903 /min 3.6 mg/str 1.660 V 85.5 *C

RPM inj.quantity Voltage Temperature

[trundlenut]

The timing is waaaaay out, far too advanced.

Sent from my Nexus 4 using Tapatalk 2

[adz1]

If the timing is "advanced" does that suggest its over fuelling? And my consumption is poor due to this?

Also will it reduce the engine noise if it comes into timing as it sounds alot louder then my brothers 1.9 TDI Seat Toledo and his is a 150bhp sport, whereas mine is a 1.9TDI 110.

Second quesiton would you guys suggest i change CTS sensor? Is it the green or black one that is good? Eurocar parts any good for this or are there parts cheap quality?

Your help will be much appreciated.

[trundlenut]

I think it means it is injecting the fuel into the cylinders too early in the cycle rather than too much fuel. This can make it noisy iirc. There is some adjustment on the injection pump sprocket which may be able to correct the timing or worst case is that the cam belt will need to come off and everything reset.

As for the CTS get a genuine one from the dealer/TPS, the revised ones are green and cost about £30.

Sent from my Nexus 4 using Tapatalk 2

[KenONeill]

If the timing is "advanced" does that suggest its over fuelling? And my consumption is poor due to this?

Also will it reduce the engine noise if it comes into timing as it sounds alot louder then my brothers 1.9 TDI Seat Toledo and his is a 150bhp sport, whereas mine is a 1.9TDI 110.

I think it means it is injecting the fuel into the cylinders too early in the cycle rather than too much fuel. This can make it noisy iirc.

As Trundlenut says, the fuel is being injected too early. This both makes the engine noisy, and reduces power, which most people compensate for with a heavier right foot, causing poor consumption.

[adz1]

Tbh the engine is noisey but most ppl tell me its common on skodas and the insulation is poor. Secondly the power is ripe ive never had issues with it feeling gutless on motorway stretches.

Brim to Brim

413.4 miles

£20 BP £40 biodiesel

MPG displayed 41.9MPG

I found this really poor however this was my first full tank after service and timing belt changed.

15miles left on range (prob 5miles in tank) i added £30 bio diesel with no mixing and it has given me 287.1 miles from 0 mile range left. MPG displayed 47.2MPG

So has my car just tuned itself up to the ECU as its giving amazing MPG now.

[bloodaxe1962]

Hi

this is begining to alarm me. I have recently got rid of an aged Golf Tdi (1996 90bhp, 218K) and bought an Octavia silverline Tdi  2003, 107K. It has only been a couple of weeks but on my 70 mile round trip to work, which I equate pretty much to extra urban driving, I was getting 62 - 63mpg from the Golf, but now I have only been getting 53mpg. Since the Extra urban for the Octy is 65ish I am wondering if there is something seriously wrong with the new engine since it is an exact match for the previous one and the drive is the same one. can I really only expect this low mpg with this car? For what it is worth the car seems to drive well enough tho' starting is less clean than the golf. I do get a slight lift in idling revs to about 1100 sometimes tho' it seems mainly to happen at startup and not always. The engine temp does seem to take a long time reaching normal; but is fine once it gets there.

Does the a/c make a difference? the golf didn't have it. I thought it only mattered if you were using it, but if it causes fuel consumption issues at all times can I get it removed?

[ruffday]

Hi

this is begining to alarm me. I have recently got rid of an aged Golf Tdi (1996 90bhp, 218K) and bought an Octavia silverline Tdi  2003, 107K. It has only been a couple of weeks but on my 70 mile round trip to work, which I equate pretty much to extra urban driving, I was getting 62 - 63mpg from the Golf, but now I have only been getting 53mpg. Since the Extra urban for the Octy is 65ish I am wondering if there is something seriously wrong with the new engine since it is an exact match for the previous one and the drive is the same one. can I really only expect this low mpg with this car? For what it is worth the car seems to drive well enough tho' starting is less clean than the golf. I do get a slight lift in idling revs to about 1100 sometimes tho' it seems mainly to happen at startup and not always. The engine temp does seem to take a long time reaching normal; but is fine once it gets there.

Does the a/c make a difference? the golf didn't have it. I thought it only mattered if you were using it, but if it causes fuel consumption issues at all times can I get it removed?

 

This is quite an old topic now but don't rely on the computer.

You need to check brim to brim. I doubt it will do more than the golf in fact I would expect less as you are running a bigger heavier car.

I have had 3 Octavia TDI's in the past a 90bhp, a 130bhp and a later 105bhp and I very rarely got over 56mpg and that was doing around 1000 miles a week.

I do have a heavy foot though. They were all bought new and swapped out at 80,000 miles.

[mac11irl]

I have a 90Bhp mk1 diesel, and i average 50 - 60mpg on most fill ups.

thats a 50miles round trip commute 5 days / nights a week and some town driving tossed around too.

in town driving the comp say 40 - 45 mpg, but i know it over estimates by 2-3 mpg....

 

Has it been serviced recently or had any work done?