My worst ever fuel consumption last week

[FrazzleTC]

I'm still getting 26 mpg, and paying 59p a litre. Can't lose!

[DMGRS]

Mine dropped down to mid-30s before Christmas - it's the cold weather.

Check your engine running temperature on the on-board diagnostics, and make sure it's up in the 80s.

[johnnyb44]

Thanks all for all your input. Its put my mind at rest as well as each others with this. Its qiute surprising really how much the colder weather can effect the mpg of a car. As you have suggested Mat I've checked the running temp and it sits between 83 and 87 degrees so its somewhere near it norm.
It will be interesting to see it improve again in the coming weeks as spring approaches ( hopefully ).

[alanjay]

Originally Posted by johnnyb44

Hi.
Last week just gone my 75 auto diesel recorded its worst ever consumption. It seems to always coincide the colder it gets. Summer usualy returns 43 ish but its now dipped to a depressing 35 this week. Im hoping this is just down to the colder weather ect and nothing else.

You should be so lucky, my 2.5 auto is recording it's worst ever average, 23.3 mpg, that's despite upgrading from Supermarket to BP fuel and replacing the Shannon tube, all of which are supposed to increase mpg.

Can only assume it's because due to cold weather I'm driving with hobnail boots instead of comfy slippers.

[johnnyb44]

That's not much fun Alan. I really couldn't afford to run a car if it was returning that much. ( not on my wages anyway ) Hopefully it will improve in time when the weather warms up.
I wonder what the optimum speed is to achieve the best MPG. Is it 56 mph as stated by official figures??.
Surely though if an auto transmission locks at around 70mph that would be the most efficient ( for an auto anyway ).

[DMGRS]

The auto will lock anywhere from around 50MPH upwards - I cruised to Essex at 59MPH in mine, and got around 55MPG. I was rather brassic at the time, some years ago!

Your temps sound fine, by the way.

[alanjay]

Originally Posted by johnnyb44

That's not much fun Alan. I really couldn't afford to run a car if it was returning that much. ( not on my wages anyway ) Hopefully it will improve in time when the weather warms up.
I wonder what the optimum speed is to achieve the best MPG. Is it 56 mph as stated by official figures??.
Surely though if an auto transmission locks at around 70mph that would be the most efficient ( for an auto anyway ).

Optimum speed/mpg is the one used for extra urban in "official" tests. Drive your car at at 62 mph (100 kph) and rev counter will show the most efficient revs. In my case 2,200 revs, trouble is I like to show tailgating Audi's and Beemers what my comfy old Rover can do.
So occasionally I use full kick down, drinks fuel but worth every penny.
Of course in this cold weather kick down costs a fortune but what the heck, anything the Germans can do we can do better.

[johnnyb44]

This week im doing the 56mph back and to from work to see if that makes much of a difference. ( revenge on the slow moving supermarket trucks ) awaits them

[andy willi]

Originally Posted by coab

Andy I used Decent fuel such as Esso and I put Iridium plugs in as they were due and they made a good 3 mpg difference according to the IPK.

my car is decated with x power exhaust and induction kit also remap and I drive like a 17 year old in a Ferrari cant really complain it is all my fault .

it's a toy to play in and I love it had the car 11 years and still makes me smile when I drive it ,

have a zt diesel for work and just fill it run it and fill it again don't check the mpg as don't have to fill it that often


andy

[Kyletrek]

Dread to think what my Zt is doing and its a diesel worst I've had was about 300 miles to a tank, I know my dads ztt can easily use a tank in about 170ish miles