Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: Beatle on January 22, 2013, 09:27:10 PM

Title: 2.5V6 Fuel Usage / Economy
Post by: Beatle on January 22, 2013, 09:27:10 PM
I've just filled up the 90 for the second time so I now have an initial fuel economy figure.  First time I filled it up the tank overflowed and filled the boot with fuel........... :o

333kms from full to low-fuel-light, using 39.9 litres (Shell Premium with a bottle of injector cleaner).

If my maths is good:
11.98 L/100km
0.12 L/KM
8.35 KM/L
23.58 MPG (imp)
19.64 MPG (US)

I have trouble grasping any number except MPG(imp), but are these numbers good, bad, or indifferent?   Most of that tank was short drives, mostly using 4th and not dropping into 5th (for the sound.....).

What is the best one could expect from a stock 75/90/GTV6 2.5 V6 on a long trip (noting my 90 has the highest gearing).

BTW, is it right that my tank would hold 50L?   I guess 40L until reserve light comes on with 10L reserve?   
Title: Re: 2.5V6 Fuel Usage / Economy
Post by: Sheldon McIntosh on January 22, 2013, 09:45:44 PM
Looks about right.  I took some figures once upon a time, and got about 13 l/100km around town, about 9-10 on the highway, and 11-12 combined.  Not great figures these days, but fairly respectable for it's day I suppose.

Tank is 49 litres.

If you filled the boot with fuel your little rubber jobbie around the fuel filler pipe must be split somewhere.  Very common, easy enough to fix with silicon, might even last a few months if you do it well.  Also, the drain hose will probably be blocked (which I guess is why they all split eventually, the petrol ends up sitting in there for a while with nowhere to go).

Oh yeah, and I worked out the consumption after a track day at PI once for the 2.5, I believe it was around 40 l/100km.
Title: Re: 2.5V6 Fuel Usage / Economy
Post by: dehne on January 22, 2013, 10:33:25 PM
My 85 mdl 90 does about 550 plus on a long trip, I would drive from Bendigo to about yass and then fill up.
Title: Re: 2.5V6 Fuel Usage / Economy
Post by: Beatle on January 22, 2013, 10:43:18 PM
Thanks Dehne,  550km from say 45 litres is 8.2 L/100 or nearly 35MPG.

And Sheldon's 40L/100 at the Island is just under 7mpg.  I haven't seen numbers like that since I last drove my petrol 80 series Landcruiser to the shops........................ :o

My petrol filler 'skirt' doesn't look torn,but I think it has come away from where it seals to the body sheetmetal.  I'll have to check/replace the drain hose and see if I can reattach the skirt.  I think part of the problem was that I'd added some injector cleaner which foamed the fuel in the filler neck.  The foam spilled out but wasn't enough to trigger the shutoff in the bowser.   This last time I filled it with the nozzle fully in the neck and the bowser clicked off a couple of times without any spillage.   
Title: Re: 2.5V6 Fuel Usage / Economy
Post by: oz3litre on January 27, 2013, 10:07:00 AM
My 3 litre Potenziata did 27 mpg around town, (10.3 l/100km), after two brim to brim refills in October last year. In November last year I got 28.25 mpg after some hills and city driving with some high revs. Earlier this month I got 25.45 mpg city with a bit more high revs than usual. Cruising at 100-110 kph on the open road it will do around 31- 32 mpg. I usually drive at a medium sort of pace with a bit of a blast occasionally. I don't use fifth at all in town, and only use it above 90 kph on the open road. I will check it again at the next refill. The engine has been ported and is running about 11:1 compression.