B14 fuel consumption

[Clan]

Well I'm now averaging 42 -45 mpg on a weekly basis , same journey every day sometimes slow moving traffic for about 20% of the journey . 2 long hills and a short steep hill to get up on the way .

How? i asked myself , I was expecting just over 30 mpg like the rest .
well:

The later 340 has a one piece rear wheel bearing , same as front wheel drive cars , lower friction than the older two ball bearing races each side .

The car has the idle valve fuel cut off as described above .

There are aerodynamic plastic pieces around the front panel and behind the bumper.
The car runs very freely and will coast for a long way , however this will not save fuel as the idle jet will not close off .


I fitted the 1.7 5 gear transaxle to replace the 4 speed M45R . the lower 4 gears are the same , 5th is higher , same rear axle ratio. I use it as often as possible .
( Perfect low mileage 4 speed M47R transaxle available )

Low friction Castrol Syntrax Synthetic Final drive oil

ATF in the gearbox not engine oil

5w/30 Synthetic engine oil .

new Vriedstein snowtrac 3 tyres @ 35 psi .

The instrument panel has the vacuum gauge .

have a 92 degree thermostat

I'm not particularly driving for economy but not exceeding 60 mph except down hill ,

Idle speed is 1000 rpm , haven’t had chance to turn it down yet .

fuel tank is filled to the brim each time ,


So there it is , still room for improvement , might fit an Oil to water heat exchanger under the oil filter to warm up the oil quicker . then drive for economy … stop/start anyone ? Fuel injection would help , must be a later Renault using this engine with injection ?

Nice to have modern car fuel economy from my 28 year old Volvo  And it goes better than any 340 1.4 i have driven before when you get the revs up .

Like the recent Driv e models there are about a dozen modifications they have done to help economy , each one on it’s own would make no noticeable difference , but the sum of them certainly does ….