Mega MPG - 160 extra miles per fuel fill-up!

Foeux · Dec 6th, 2023, 07:07

Dear Chums,

I recently solved a bit of a misfiring and rough running puzzle with my 233,000 mile 940 estate (2.3 non turbo). Here is a link to it.

If you can't be bothered to read the whole thread, I replaced most things to do with fuel and spark (plugs, leads, cap, arm, INJECTORS, ignition amp, coil, idle air valve).

It is now running well and we are friends again. I drove a 100 mile journey yesterday and thought I'd do the nerdy 'brim to brim' mpg calculation. I drove Devizes to Ringwood and back. There was some national speed limit, some town, 6 mins of being sat still in traffic idling.

The journey was 97.1 miles. The car used 11.35 litres of fuel (filled up at same pump at same station for extra science)

97.1mi ÷ 11.35L = 8.56 miles/litre.

8.56 miles/litre x 4.545 = 38.88mpg

I was previously getting low 30's and often high 20's mpg. This is ace!

75 litre tank ÷ 4.545 = 16.5 gallons

16.5 gallons x 10mpg(ish) = 160 miles per tank.

These findings are quite pleasing BUT are not perfect. 1) the car could have been running rough since I got it and only now is it 'back to standard'. 2) the journey to Ringwood is a nice smooth one and there wasn't much chance to break the speed limit. 3) time will tell.

Anyone else done injectors and seen a big jump in mpg?

Cheers,

F

Moomoo · Dec 6th, 2023, 08:06

Early Christmas prezzie!🥳🥳🥳

J liddy · Dec 6th, 2023, 08:18

Very good news that nearly beats my 940 diesel .on a long motorway run I archived 40 mpg doing the same process. But around town now I only get 30
ma ximum now on very cold frosty days

tofufi · Dec 6th, 2023, 08:44

Great stuff.

Measuring fuel economy over a relatively short distance would show more effect from the type of journey, but it sounds like a combination of both a 'good' journey and a better running car in your case

My D24T averaged nearly 46MPG over the 35,000 miles or so I've done in it. It doesn't do many miles any more, but all the runs it did were long journeys at motorway speeds.

I got it up from 43MPG when I first got it with a few minor tweaks and routine servicing

baggy798 · Dec 6th, 2023, 18:21

It's normal to have around a 10-15% mpg drop in winter, so 39 is amazaazaazing.

Dec 6th, 2023, 07:07	#1
Foeux Senior Member Last Online: May 22nd, 2024 18:37 Join Date: Dec 2013 Location: Wiltshire	Mega MPG - 160 extra miles per fuel fill-up! Dear Chums, I recently solved a bit of a misfiring and rough running puzzle with my 233,000 mile 940 estate (2.3 non turbo). Here is a link to it. If you can't be bothered to read the whole thread, I replaced most things to do with fuel and spark (plugs, leads, cap, arm, INJECTORS, ignition amp, coil, idle air valve). It is now running well and we are friends again. I drove a 100 mile journey yesterday and thought I'd do the nerdy 'brim to brim' mpg calculation. I drove Devizes to Ringwood and back. There was some national speed limit, some town, 6 mins of being sat still in traffic idling. The journey was 97.1 miles. The car used 11.35 litres of fuel (filled up at same pump at same station for extra science) 97.1mi ÷ 11.35L = 8.56 miles/litre. 8.56 miles/litre x 4.545 = 38.88mpg I was previously getting low 30's and often high 20's mpg. This is ace! 75 litre tank ÷ 4.545 = 16.5 gallons 16.5 gallons x 10mpg(ish) = 160 miles per tank. These findings are quite pleasing BUT are not perfect. 1) the car could have been running rough since I got it and only now is it 'back to standard'. 2) the journey to Ringwood is a nice smooth one and there wasn't much chance to break the speed limit. 3) time will tell. Anyone else done injectors and seen a big jump in mpg? Cheers, F

Dec 6th, 2023, 08:06	#2
Moomoo VOC Member Last Online: Yesterday 20:21 Join Date: Aug 2021 Location: Ashbourne	Early Christmas prezzie!🥳🥳🥳 __________________ It’s pointless having a battle of wits with unarmed people!

Dec 6th, 2023, 08:18	#3
J liddy Senior Member Last Online: Yesterday 07:26 Join Date: Jul 2019 Location: Stoke on trent	940 TIC auto 1995 .301000 miles Very good news that nearly beats my 940 diesel .on a long motorway run I archived 40 mpg doing the same process. But around town now I only get 30 ma ximum now on very cold frosty days

Dec 6th, 2023, 18:21	#5
baggy798 🤍💙💗 Last Online: Today 02:46 Join Date: Mar 2006 Location: Lichfield	It's normal to have around a 10-15% mpg drop in winter, so 39 is amazaazaazing. __________________ MY97 940 CD LPT Super Sports Edition 2 Turbo, Midnight Purple, 175,000 miles.

Dec 6th, 2023, 08:44	#4
tofufi Premier Member Last Online: Yesterday 19:40 Join Date: Sep 2014 Location: Bristol	Great stuff. Measuring fuel economy over a relatively short distance would show more effect from the type of journey, but it sounds like a combination of both a 'good' journey and a better running car in your case My D24T averaged nearly 46MPG over the 35,000 miles or so I've done in it. It doesn't do many miles any more, but all the runs it did were long journeys at motorway speeds. I got it up from 43MPG when I first got it with a few minor tweaks and routine servicing

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