1990 Peugeot 405

[jriley]

Greetings from Slovakia, a less known country of the EU.

I own an old french-built Peugeot 405 as a 2nd car. It was intended for the scrapheap several years ago but the old gal just keeps on going. It serves as my daily commuter clocking up 80 miles/day (40 mile round trip) and for the fun of it I'm looking for ways to boost the mileage a bit.

For those of unfamiliar with french cars I'm posting a brief description:

The car is equipped with a 1.6 liter 8-valve gasoline engine designated XU5M (BDZ) by the PSA group (Peugeot, Citroen). At the time, the engine was available in carbureted, monopoint and multipoint injected versions. Mine has a monopoint injection system from Solex controlled by a Magneti Marelli G5 ECU.

It is equipped with the original catalytic converter and lambda sensor, followed by mid and tailpipe silencers. The engine outputs 88 hp, runs great and uses next to no oil. Factory specs call for 10W-40 oil which is what I use.

It's coupled to a 5-speed manual transmission (designated BE5) which shifts as well as day it left the factory. The specs call for 75W-80 oil which is what I use. At 65 mph (typical driving) the engine runs at 2900 rpm in top gear.

This car is really low on equipment having next to no power accessories: steering, windows and mirrors are all manual and the ventilation has no AC. It's also quite light for it's size with only 2300 lbs including the driver and fuel (as observed at the MOT). I wears a set of stock 14" tires with 185/65 width and sidewall.

Whilst rated at 7.4 l/100km (32 US mpg) I regularly manage 6.3 l/100km (37 US mpg) by driving it in low revs under load.

That said I would like to tinker the mileage up a bit, just for the sake of a little fun. Fuel costs aren't really that important as I can cover them, plus I suspect any substantial gains aren't possible (or sensible) on a car this old anyway.

Any suggestions as to what could be done to this old banger?

Cheers.