Strange Mpg

[btmaldon]

This is strange, but cannot all be due to poor quality Asda petrol.

I filled the tank up on Saturday at Asda, did around 10 miles of running around. Set off for Oswestry in Shropshire Sunday morning, which is 215 miles from our house. I was hoping to get there and back on a single tank.

As it is nearly all Motorway, I kept it at 70. I normally get 41 to 43 on a run if I keep it at around 80 or less. I thought I may be able to get 45 out of the Focus if I took it easy.

After 100 miles, I checked the average mpg, only to find it had only achieved 36mpg. This is the worst result so far. So I put my foot down for the rest of the journey and still achieved 36mpg.

So I had to fill up as I didnt have quite enough fuel to get home. Filled up at the Esso Garage just outside Oswestry, did a steady 80 to 85 all the way home and averaged 41mpg.

Now is Asda petrol that bad (normally fill up there and its never that low)or is it likely to have been a bad batch?

The car has only done 3000 miles from new.

[Chutney]

Have you comsidered the altitude of the two locations?

[fernsie]

Inclines are the killer.

I live in the central belt of Scotland and drive the M8 almost every day

Most people don't releise that when they leave Glasgow, or Edinburgh that the M8 is an incline to about the half way point, with the incline being steeper on one side than the other ... what this means for me is that I get about 44mpg coming home from work (driving like a saint), but 60(ish)mpg on the way to work, even with a little more gusto

I dare say the fuel can make a difference, but unless you drive exactly the same road with same traffic conditions regularly, it's very hard to quantify

[btmaldon]

I normally get over 40 when I drive to Shropshire, and I am up there every 6 or 7 weeks. I cant put it down to altitude or the landscape as I use the same route. Traffic was better than usual and there were no jams, so no stopping and starting either.

[Chutney]

Again, as in other posts... The likelyhood is that your trip computer was not 'telling the whole truth and nothing but the truth'.

A slight head wind can make a massive difference to fuel economy (5mph head wind on my VX220 would create a 5mpg difference on a motorway journey, a 35mph head wind had a 15mpg effect), along with moisture in the air. Additionally by putting half a tank of Shell fuel in wouldn't make that much of a difference, as the remaining ASDA fuel would only be half (or so) diluted by the fresh stuff.

There are too many factors involved in fuel economy for anyone to just outright state a cause.

[btmaldon]

Sorry for bringing up this old thread again, but I am now convinced that the Asda Petrol is the cause for poor fuel consumption. Certainly what we are getting in my location anyway. This only seems to have been the case since November.

I have been to and from Shropshire 3 times in the last two months. Ive done the journey loaded up and unloaded each way. Every time when I fill up with Asda fuel I get 36 mpg and coming home I get 41 mpg because I filled up with Esso before returning.

Also our SportKA has developed an emmissions fault and is running pretty rough at the moment, which may possibly be due to the fact it is always filled up at Asda and two of my friends cars have their emmissions lights on. Their cars are less than two years old and they also fill up at Asda.

Unfortunately Asda's is the only garage near us, so in future I shall be doing everything I can to avoid having to use them.

[jeebowhite]

Sounds like a royal pain there btmaldon, unfortunately this is the burdon of the fuel market competition, giving you cheap fuel because its filled with more cack than oils. Unfortunately its unavoidable where you are by the sounds of it, but maybe incorporating a fuel up whilst out of the area every week will be beneficial to you.

Have you tried the likes of the lead fuel additive to see if that helps you improve partially your MPG?

[pragmatix]

Part of the problem might be tempreture, you say it started in November, thats when it started to get colder, so that would make sense as fuel consumption gets worse the lower the temp

[btmaldon]

Part of the problem might be tempreture, you say it started in November, thats when it started to get colder, so that would make sense as fuel consumption gets worse the lower the temp

If it is temperature it is only affecting the Asda fuel. The drives to and from Shropshire are weekends normally and the temperature will be the same on the way up and back again. In the summer I was getting 42 to 43 on a run to Shropshire in both directions.

I have always expected some variance between Supermarket and branded fuels as I have experienced it in the past with older cars, but not to this degree with a car with only 5k miles on the clock.