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Discussion Starter #1
After tuning up the stock 351c in my P5 LTD I fuelled up and went for a drive. 215km's later I re-fuelled and discovered I'd used 45 litres of fuel, thats 4.7 k's per litre. She has a new 600 sq bore Holley and runs smooth but does ping if I use more than about half throttle. Timing is 5* BTDC static and about 34*full (vac advance disconnected). I think the pinging is the LRP fuel.
What sort of fuel economy should I expect because this seems very poor, I've got a mild 350 chev in a Monaro thats giving me twice the performance at near 2/3rds the consumption and without any of the pinging problems, and I drive that hard. :wnc:
 

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Driving hard makes your economy go down in an exponential way!! I always say that "this week" I'm going to drive normally and see what I get.....but it never works!

What gear diff ratio's do you have (or RPM @ 100kmh)?? Overdrive gearbox??

20L/100km (~45L/215km) is about what I get in my 351 XD......but that's running 4.11 gears and screaming at [email protected] Booting it hard out of every corner and I'd expect about double that! You should be getting way better - TUNING IT UP nice makes a big difference.

Try running BP Ultimate 98 (with a valve addative). I bet your pinging will disappear - you may even be able to crank up the timing a little (which helps economy)! It costs a little more to fill up - BUT - its way better than LRP and it also contains more "energy" for the same amount of LRP - ie:you'll use a less and your economy goes up. LRP is supposedly about 95-96 octane?? I just changed over to BP Ultimate - totally different!

Cheers
 

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Slurry Boostin
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To much advance I'd suspect for your motor.

Don't run LRP. Use any kind of premium fuel. I prefer BP Ultimate or Optimax.

Economy is fairly achievable.

I have a fairly warm 351, 750 DP, toploader, 3.9's putting out 234rwkw and I haven't worked out economy yet but drove from Pakenham to Lakes Entrance not creeping along, 120kph pretty much all the way, on around 30 litres. It is roughly 250kms distance.
 

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Discussion Starter #4
I'm still to try the 98 PULP but otherwise the engine is fairly well tuned. This car is totally stock with 2.75:1 rear, FMX, 351c and is driven very conservatively (rarely sees over 2500rpm). The only thing I've changed is a new 600 Holley which is causing the engine to run on when I shut it off.
 

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Never enough Horse Power
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I have had a little bit done 2 my 351c and around town I have no fuel economy but I like givin it a sqiurt here and there but on a trip its reasonable. About 400 kays to 65 odd litres of Optimax
 
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