Hello Everyone,

I've been struggling to figure this out on this car for a couple of years. I've been getting terrible fuel economy when it's cold outside (~0-deg celcius is where it starts, but lately it's been ~-15-deg celcius and it's been terrible).

The car is a 1986 760 Turbo, so I think it likely has a 4.10 rear-end in it and the turbos aren't particularly good on gas as I understand it anyway, but in my case the difference from warm temps to cold temps is just really huge and hard to ignore.

In the summer (~+30-deg celcius/~+80-deg F) I can get ~500km on 55L of fuel.

Last week (~-18-deg celcius/~0-deg F) I got ~250km on 50L of fuel.

That's basically half. It's like this every winter.

In previous years I've been suspicious of various things being old/worn out/acting strange, but this winter everything is working really great on the car. All vacuum hoses have been changed recently, plugs (~10k kms ago) and wires and rotor cap (~40k kms ago) changed, air filter changed (~40k kms ago), same fuel, tire pressure is good, trans fluid is good, oil is about 3500 kms old.....


Any ideas about what gives?
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1986 760 (B230FT) 420k+