Questionable MPG

Psymonkee · 13 Jun 2012 at 00:54

Hey,

Got a feeling there is yet something else wrong with my car given the trip computer data from today's driving:

192 miles @ 51mpg (has used ~half tank), computer says 235miles left.

192+235= 427 miles range.

Only thing is my car has never reported anything higher than 48mpg (including a run from St.Andrews -> Swindon) and based on that trip it should be capable of 550 miles on a tank!

Any ideas? Something doesn't add up but I can't figure it out :confused:

PiKe · 13 Jun 2012 at 00:56

O2 sensor going dodgy?

Matt82 · 13 Jun 2012 at 06:42

How have you calculated the figures you're comparing to the obc?

Raymond Lin · 13 Jun 2012 at 07:08

48/51, it's not that big a difference is it?

CaptainRAVE · 13 Jun 2012 at 07:12

Worst look at my MPG thread ever.

Iamzod · 13 Jun 2012 at 12:33

Psymonkee said:
computer says 235miles left.

192+235= 427 miles range.

Don't trust the miles left, i've had my Mondeo recalculate towards the end of a tank and suddenly decide that instead of 40 miles left i now have over 100.

It happens when i've done a really long few hundred miles steady motorway drive.

Dogbreath · 13 Jun 2012 at 12:34

Raymond Lin said:
48/51, it's not that big a difference is it?

Especially not from a trip computer as they are notoriously inaccurate on many cars.

Simian · 13 Jun 2012 at 12:51

If you've got an Android Phone, Get this App https://play.google.com/store/apps/details?id=ch.simonmorgenthaler.fuellog#?t=W251bGwsMSwxLDUwMSwiY2guc2ltb25tb3JnZW50aGFsZXIuZnVlbGxvZyJd and keep tabs on your MPG for a couple of months!, if things still look a bit dodgy then take it to the garage!!

Sim

Janesy B · 13 Jun 2012 at 12:53

Simian said:
If you've got an Android Phone, Get this App https://play.google.com/store/apps/...wMSwiY2guc2ltb25tb3JnZW50aGFsZXIuZnVlbGxvZyJd and keep tabs on your MPG for a couple of months!, if things still look a bit dodgy then take it to the garage!!

Sim

Bear in mind that MPG calculators like this depend on your filling the tank up, driving and then filling it to full again - obviously then it'll work out the MPG for the distance covered and the amount of fuel needed to fill the tank. It won't work if you top up with a tenner each time.

s0ck · 13 Jun 2012 at 13:23

What car, op? Something VAG based?

As an aside, I put 3 quid of petrol in once.
"Three... pounds?" stammered the shop assistant.

Raymond Lin · 13 Jun 2012 at 13:28

s0ck said:
What car, op? Something VAG based?

As an aside, I put 3 quid of petrol in once.
"Three... pounds?" stammered the shop assistant.

I beat that...£2.67 for me the other day.

I filled up the tank when I got to my B&B, then went to Peterborough (20 miles) and went to top up my tank so I got a full tank for the day after, as I have wedding shoot, church to venue and then a 3 hours drive home the day after so I wanted enough petrol for all that.

Anyway, I JUST hit 2 Litres when it clicked lol

Paid by card too

s0ck · 13 Jun 2012 at 13:32

Damn you!

In my defence, I was running veg oil at the time and the ambient temperatures went proper cold so I followed some popular forum mythology that said 'try some petrol in it'.

Car ran like an absolute dog for that tank, so can't recommend it

DB_SamX · 13 Jun 2012 at 13:42

Simian said:
If you've got an Android Phone, Get this App https://play.google.com/store/apps/details?id=ch.simonmorgenthaler.fuellog#?t=W251bGwsMSwxLDUwMSwiY2guc2ltb25tb3JnZW50aGFsZXIuZnVlbGxvZyJd and keep tabs on your MPG for a couple of months!, if things still look a bit dodgy then take it to the garage!!

Sim

Excellent; will grab that.

Janesy B · 13 Jun 2012 at 13:49

Raymond Lin said:
I beat that...£2.67 for me the other day.

I filled up the tank when I got to my B&B, then went to Peterborough (20 miles) and went to top up my tank so I got a full tank for the day after, as I have wedding shoot, church to venue and then a 3 hours drive home the day after so I wanted enough petrol for all that.

Anyway, I JUST hit 2 Litres when it clicked lol

Paid by card too

How much fuel did you expect to use in 20 miles? :confused:

Raymond Lin · 13 Jun 2012 at 13:52

Janesy B said:
How much fuel did you expect to use in 20 miles?

Lots and lots, like 99% of the tank lol

The point was i wanted to fill the tank, the point wasn't thinking about how much I've used

Lustral · 13 Jun 2012 at 14:29

Raymond Lin said:
I beat that...£2.67 for me the other day.

I filled up the tank when I got to my B&B, then went to Peterborough (20 miles) and went to top up my tank so I got a full tank for the day after, as I have wedding shoot, church to venue and then a 3 hours drive home the day after so I wanted enough petrol for all that.

Anyway, I JUST hit 2 Litres when it clicked lol

Paid by card too

Dont most petrol stations have a minimum delivery or 5 litres or something ?

Wait or 2 litres

Raymond Lin · 13 Jun 2012 at 14:37

Lustral said:
Dont most petrol stations have a minimum delivery or 5 litres or something ?

Wait or 2 litres

2L, hence the "phew!" moment lol

Lustral · 13 Jun 2012 at 14:53

Raymond Lin said:
2L, hence the "phew!" moment lol

Usually when the pump clicks , i dunk in to the next second £ anyways.

Yesterday. i was filling and it clicked on about £35.10 , i filled up to £37 anyways. Usually you can prolly squeeze another litre or so after the 1st click i find on most cars that i have filled up.

Simian · 13 Jun 2012 at 15:59

Janesy B said:
Bear in mind that MPG calculators like this depend on your filling the tank up, driving and then filling it to full again - obviously then it'll work out the MPG for the distance covered and the amount of fuel needed to fill the tank. It won't work if you top up with a tenner each time.

Been using it for about a year now! I have to Fill/Brim my car otherwise I can't get to work and home again (Every 2 round-trips)..

I say's my 10 year old Civic 1.4 Vision is giving me an average of 44mpg

"andy" · 13 Jun 2012 at 19:35

Lustral said:
Usually when the pump clicks , i dunk in to the next second £ anyways.

Yesterday. i was filling and it clicked on about £35.10 , i filled up to £37 anyways. Usually you can prolly squeeze another litre or so after the 1st click i find on most cars that i have filled up.

If you brim it then drive into a sudden heat wave where's the expansion going to go ?