Thread: 94 Vogue SE Fuel Economy

About 19-20L per 100Km around town is about right.

On the highway you should get around 15-16 on a flat road at 100Kmh.

The official figure from UK was AFAIR about 20MPG at 75MPH. they actually lean out at that speed to obtain that figure so don't plan on it. In addition in UK it was with catalysts and a high compression motor.

You can do what I did and spends lots of money trying to get better economy but they are a basic fuel injection , in a 1960 design engine, pulling over 2tonnes and the dimensions of an outhouse.
Regards Philip A

Apart from advancing the ignition timing to around 10 degrees BTDC at idle there's little you can do easily to improve on your figures. Oh and in polite RR owning circles One doesn't speak of economy, One speaks only of satisfactory performance!

my 1991 vogue se 3.9 is using around 24l/100m some times more

Looking at the fuel spreadsheet, in just over 5 years of ownership and 48,000k, I averaged 21.72L/100k for my old soft dash classic.

Best was approx 17l/100km on the highway and worst just under 26l/100km towing the caravan. Around town was around 22l/100km.

Cheers

Steve

Looking at my expense tracker for my 1992 3.9 with Thor manifold, I have averaged 19.3ltr/100km over the last year of daily commuting along a notoriously congested Pennant Hills Rd followed by a 7km run on the M2. The best I have for a single trip is 13.17ltr/100km, cruising at 90kmh along the M1 from Hornsby to Taree (looks suspiciously low but I have checked and rechecked the numbers?).
I have also recorded 14.17 and 15.23ltr trips

Geez Bigdog, I spent countless hours and mucho dinero to get those figures!


The car has Unichip, 3 or 4 sets of dyno runs, Thor manifold, o2 sensors, modified heads, free flow exhaust, snorkel , Bosch yellow injectors, 717 coil etc etc.
I once saw 13.7 at 100Kmh from Mt Isa to Longreach towing my camper trailer.
Hence my comment that IMHO it is not worth the effort.


But great to see that she is now going strong again.


I think the best single change was the Unichip but it cost $1400. The Thor was more to shift the torque curve lower for towing.


In sheer fuel economy gains it is not worth it, but the old girl gets up and boogies.


Regards Philip A

Originally Posted by 94VogueSE

I would like to know what sort of economy I should be getting on my RRC. It's a 94' Softdash Vogue SE, auto trans. 3.9 V8, non catalyst.

So far, it seems to be doing 19-20L/100km. I only get to do around 330km from a full tank, until the low fuel light comes on.

It is driven on a mix of urban and freeways, mostly driven sedately.

Engine feels quite strong and pulls along quite well. Is my current economy about right, or should it be better? Bit of a shame it shows the low fuel light after only 330km.

It has had a recent oil change, and air filter change. I have also cleaned the MAF, only by spraying MAF cleaner through the mesh, rather than dismantle it and spray direct into the hole.

I sometimes get 380km per LOW FUEL light.. Fuel gauge is an abuse of the English language.... And the tank's lack of capacity is an embarassment.

Banish your off-road ambitions... go back to skinnier tyres, ditch the roof-rack / bars as well as the bull-bar, keep the IGN system in 101% condition, drive it even more gently and....

Aw, forget it. Buick were happy to see the back of that engine 'cos they knew it was a lemon regarding power/fuel use...

Bank on $30 per hour on the open road, $20 around town, and that will make it's Drinking habit a tad more bearable...

But they are nice to drive.

The Lady Sarah, 95 Softdash with working air suspension

Buick couldnt have cared less about mpg,,
it was the constant oil leaks that made them sell,, seriously.