Thread: RRC Fuel consumption drama

My 1992 auto RR on gas is giving me 30 lt /100km. around town. I have been told that is to be expected. It runs sweet but my wallet is complaining with gas being 55 to 60 cents /lt up here.

Fluffy doesnt use that much fuel but here is something that made a noticable difference to the consumption. I always use 95ron as if I use 91 or 98 the consumption rockets up to 25L/100.

I noticed the around town consumption on fluffy was creepin up by 2L/100. She runs sweet and usually never uses over 20L around town.

My mate nottie advised to check the resistance on the two outer connections on the AFM...I removed the plug and wacked my multimeter on to check it and I got a total resistance of 71.4ohms. Factory specs is 174ohms so I set it too that.

That's all I changed, and so far after three tankfuls I have been given the impression that the fuel consumption is actually better then previous, and that is always gonna put a smile on my dial.

So am gonna wait to use a few more tanks and then check the resistance of other components (tps is next).

Something everyone should be checkin I guess. I was also under the impression that higher resistance was leaner, but rick told me otherwise, so going by that i efectively richened up the total mixture with absolutely no noticable change to the exhaust fumes and better fuel economy.
Power feels exactly the same and engine temps havn't changed either.

I did same, put proper tyres back on and see the difference.
The old tyre debate is always something that gets me.
Big tyres create drag and are way less efficient.

try it and let us know.

Sure Big wheels look good to some folk but do very little for mech wear and actual handling and off road performance.

Originally Posted by big guy

Sure Big wheels look good to some folk but do very little for mech wear and actual handling and off road performance.

Sorry but I have to dissagree about the offroad performance bit.

Everything else is spot on thou

Originally Posted by Grimace

Fluffy doesnt use that much fuel but here is something that made a noticable difference to the consumption. I always use 95ron as if I use 91 or 98 the consumption rockets up to 25L/100.

I noticed exactly the same thing! When fuel prices dropped here, I started filling up with 98 at first to give it a clean and got about the same as the 91, but 95, i recorded down to 16L/100km, and thats after I found out my vac advance isnt 100% kosher!!
Did a country run over New Years with a good 800kgs towing behind, full car and a pod and got 20-21L with 98!
98 really needs a bit more compression to get it to burn well, anyone with a 9.35:1 CR will do well but an 8.13:1 which accounts for all unleaded Classic RR's without a cat convertor, 95 is the shot.

Regards

Andrew

Did you get the them bottom of the problem?

Have you checked your brakes? I know it sounds silly but (please don't bash me for mentioned another marque) but on my Jeep, one of the calipers was stuck, which obviously increased the resistance and therefore fuel consumption. It may not be particularly noticable but add to the consumption.