CR170 vRS fuel consumption conundrum

[Brimma]

About to embark on a 360 mile round trip to Carlisle and back today and the fuel gauge was showing nearly empty

Went to the local station and pur in £69 of diesel @ 137.9p/l, so approx 11 gallons

Outward journey, at reasonably quick motorway speeds, maxidot showed 45.4mpg, homeward journey it showed 44.8mpg

Problem - when I got back tank was showing as almost empty, with a range of less than 20 miles, ie lower than when I filled up

Total milwage recorded there and back was about 368, so that equates to a horrifying 33.45mpg

Now I'm fully aware that maxidot isn't accurate, but surely not 11-12mpg out

Calibration of maxidot speed/distance reading must be about right, as the distance travelled is correct

So what's the crack?

Car's only just been serviced and MoT'd, so I can't think there's a fuel leak

[FUBAR]

No idea why but my 06 Mk1 Fabia VRS was getting great 65mpg when I wanted it and overall average over 10-12K of 53mpg driven without real care for MPG and a lot of cold start short sprints. Had it serviced at main dealers and I suffered a massive rise in fuel consumption immediately dropped by about 12-15mpg it levelled out again a bit more later on but I couldn't explain it at the time. My only though was did they use the wrong oil or something, car felt the same to drive though.

You have one of the early CR's I assume it has the same DPF set up as the FL's with its more modern regen system, perhaps a few aborted cycles along the way that kept starting again? You could have a quick look on VCDS.

at reasonably quick motorway speeds

your definition of reasonably quick motorway speeds may differ from others, no one will prosecute you for giving the approx figure. I can easily achieve 55mpg or sub 30mpg speed being the varying factor on motorways.

[Brimma]

I'm sure it was under 90 at all times.........or was that the oil temperature?

[FUBAR]

I'm sure it was under 90 at all times.........or was that the oil temperature?

I would expect my MPG to be around the same at that speed would that be your normal sort of motorway speed? Maybe like with a speedo the amount it varies of being off grows with the speed?

[Brimma]

I would expect my MPG to be around the same at that speed would that be your normal sort of motorway speed? Maybe like with a speedo the amount it varies of being off grows with the speed?

What I can't understand is why the maxidot figure is so far wrong

[FUBAR]

26% is a fair change! Have you actually brim it brimma to work out exact final MPG figure? Predicted range could be down from its low mpg run?

[Brimma]

26% is a fair change! Have you actually brim it brimma to work out exact final MPG figure? Predicted range could be down from its low mpg run?

I haven't topped up again - the thought of £140 in a day was a bit too much swallow. I did put £30 in though, and it's less than half full

Might be a good excuse for having the DPF removed, just in case that's killing the consumption

[kevberlin]

My maxi dot and actual consumption figures appear to be almost the same. The Range figure shown on maxidot also appears to be accurate.

I know this doesn't help you, but at say 75mph motorway speeds I'd expect about 48mpg.

[silver1011]

Different engine I know but bear with me.

65 mile commute at speeds between 60mph and 80mph.

When I first got my PD170 vRS the Maxidot showed between 52mpg and 58mpg. Actual average mpg = 48mpg (calculated manually).

Had it serviced.

Maxidot has never been close to 50mpg+ ever since. It now reads between 35mpg and 45mpg. Actual mpg is still 48mpg.

Something weird went on during the service.

[Kiwibacon]

Until you fill it up again, it's just guesswork.

But at 90mph or thereabouts, 33mpg is probably right. Did you reset your MPG meter before you left is that giving you the average over a much longer distance?

My PD140 maxidot is about 6% optimistic.

[silver1011]

As above my PD170 averages 48mpg, it spends approx. 70% of it's time at 80mph.

The CR is more fuel efficient.

33mpg isn't right, something is amiss.

[FUBAR]

As above my PD170 averages 48mpg, it spends approx. 70% of it's time at 80mph.

The CR is more fuel efficient.

33mpg isn't right, something is amiss.

Pulling a big old bus like brimmas at 90mph id expect the drop from 80-90mph to be dramatic likewise with most diesels. Any passengers or coffins on board would obviously affect it too.

[Brimma]

I actually left the radio off all the way there as well, as I know that canes the fuel economy

[FUBAR]

I actually left the radio off all the way there as well, as I know that canes the fuel economy

Perhaps your DIY Columbus is running its fan all time taking all the power :p did you update the gateway for it? I have heard those old Skoda's needed something done to accept the upgrade.

[stu220]

My car is a 12 plate Vrs CR.

I do a minimum of 85 miles a day and my Maxidot shows an average of 50.5 MPG in the last 4k miles. True consumption is 47-48 per tankfull calculated brim to brim. My drive is down the A299 and M2 during rush hour so avg speed is 55-65 mph.

A trip to northern Holland via France let the car really stretch its legs and it cruised at a steady 130 KPH for hours, loaded with 2 adults, 3 kids and full boot (estate). Real consumption fell to 45 MPG and maxidot to 48.

Above 70 mph the consumption goes up a huge amount especially 80-90.

[mr_awol]

I want to know where te OP is getting his derv from. I try not to look but round here it ranges from 141.9 on149.9

Generally I get about 400 miles from a tank and average 38mpg (Long term calculated). I haven't checked the OPs calls but are they definitely right?

[kris1]

It's 138 round here in gods own country (Yorkshire)

I pay 147 for vpower !

[Brimma]

It's looking as though I need to remove some lead from my boots :(

[eccleshill]

It's looking as though I need to remove some lead from my boots :(

But that doesn't explain the discrepancy between maxidot and observed fuel usage. What difference do you normally find? A leaden boot should affect both equally.

I checked your figures - they are correct

Your £69 bought you 50 litres. After your trip the fuel gauge was lower than before but lets assume you used 50 litres.

Assuming your maxidot is 10% optimistic then that says 40mpg

At 40mpg your 370 mile round trip should have used 42 litres.

You have "lost" 8-10 litres.

You said

Car's only just been serviced and MoT'd, so I can't think there's a fuel leak

I would say

Car's only just been serviced and MoT'd, what did they leave loose

I think you should be looking for a leak! Fuel filter?

[Brimma]

You said

Car's only just been serviced and MoT'd, so I can't think there's a fuel leak

I would say

Car's only just been serviced and MoT'd, what did they leave loose

I think you should be looking for a leak! Fuel filter?

That might be a good shout, I did jokingly mention a leak, but it could be a live option

[FUBAR]

Just took the car into the father land and managed only 55mpg from cold start with Shell V-power 70 miles round trip inc 30miles on autobahn at just under 70mph :( I was really trying too lol this would be perfectly reasonable but I have my winter alloys on and that normally gives me a little boost in MPG with the lower rolling resistance.

[Guest]

Just took the car into the father land and managed only 55mpg from cold start with Shell V-power 70 miles round trip inc 30miles on autobahn at just under 70mph :( I was really trying too lol this would be perfectly reasonable but I have my winter alloys on and that normally gives me a little boost in MPG with the lower rolling resistance.

Never saw 55mpg in my old cr vRS. My long term average was 37/38mpg. You lot drive too slow ha

[James I]

I have the CR 170 in the Yeti, maxi dot shows 43mpg for the overall average however because I record mileage on the fuel receipts and Arval collate all the data for miles travelled and fuel used, I can confirm that for the last 61,000 miles the car has done 37.24mpg not the 43mpg as maxi dot suggests.

I have also noticed if you keep the rpm below 2,000 you will get loads of miles to your gallon, if you knock on a bit this plummets, I got a terrible 29mpg for the trip from West Thurrock to St Helens once, it only took 3 hours door to door but used nearly a full tank of diesel.

Did I mention that Gold is heavy?

[Brimma]

Did I mention that Gold is heavy?

It's only 9ct, not 24

Who do you think I am, Rockerfella? :(

[FUBAR]

Never saw 55mpg in my old cr vRS. My long term average was 37/38mpg. You lot drive too slow ha

I might need this car to last a long time so I am nice to it but I can easily on same run have it show mid 20's mpg when the autobahn is used to the cars full potential. My over all long term average at moment is prob lower than yours was as its normally only doing short runs cold start and stop ones then sits for weeks then might do 3000 miles in a week.... its random driving tbh.