FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: Not Happy Jan on December 09, 2012, 10:40:08 PM



Title: Fuel economy
Post by: Not Happy Jan on December 09, 2012, 10:40:08 PM
I have not taken too much notice of fuel economy up till now as it seems to be getting worse
I filled up today with 35 l and have only done 153 miles. Which is 9.2 gallons which is a touch over 16.5 miles per gallon if my maths is correct .
I should be getting around 22 mpg or better shouldn't I ??
It's been recently tuned and timing is good. Would tapped mal adjustment affect fuel economy that much?
Nick


Title: Re: Fuel economy
Post by: KFH on December 10, 2012, 09:54:27 AM
Nick. That seems to indicate a large tuneup problem.  Ignition timing, carby jets blocked/incorrect size etc or stick/burnt valves. I doubt very much if tappet adjustment would cause any significant difference to economy.  Does the car perform as expected? I assume you are running a 132/138 grey.  I run a 132 grey and on highway trips regularly obtain 28.5 to 29 MPG with 23 MPG running around town.  The speedo and odometer are accurate.  Presently I have a 3.89 diff.

Keith


Title: Re: Fuel economy
Post by: KFH on December 10, 2012, 10:01:14 AM
Nick.  Previously I did not run calculations on the figures you gave.  It actually works out to 19.86 MPG.  Not real brilliant.  Was this city running with heavy acceleration?

Keith


Title: Re: Fuel economy
Post by: Not Happy Jan on December 10, 2012, 12:55:02 PM
Thanks Keith... its a 10k pretty easy trip to work with no traffic. it performs well good pickup etc.
i'll give it another tune and check the carbies. do a compression test etc.
told you my maths was suspect. ;D
Nick


Title: Re: Fuel economy
Post by: jwm on December 10, 2012, 05:46:10 PM
It sounds a little like 'short trip' syndrome might be contributing to the problem. 10klms is not far and certainly doesn't give the car much of a chance to get up to proper operating efficiency. Try a longer run.

Just my thoughts.


Title: Re: Fuel economy
Post by: colt on December 10, 2012, 05:56:20 PM
I agree. Just worked it out myself to 19.8 mpg. Go for a longer run and check it again.

Colin.


Title: Re: Fuel economy
Post by: Not Happy Jan on December 10, 2012, 08:30:16 PM
Thanks boys.... I'm going for a drive to Coffs Harbour in the next few weeks so i will do another reading!
To work out the fuel economy isn't it 153  divide by 9.2  ???
Nick


Title: Re: Fuel economy
Post by: FCGos on December 10, 2012, 08:40:50 PM


There is 4.546 litres to a gallon, which means you should divide by 7.7 for 35 litres used 


Title: Re: Fuel economy
Post by: Maco on December 10, 2012, 08:47:03 PM
Nick,

When you calculate the fuel economy you should consider the tyre size, the diff ratio & also how large is your R foot.

Cheers
John


Title: Re: Fuel economy
Post by: KFH on December 10, 2012, 11:04:18 PM
The method I use for fuel economy, and there will be other ways, is multiply miles traveled x 1.609 to obtain kilometers.  Divide km's by ltrs used.  This gives km's per ltr.  Multiply this reading by 2.8245 to obtain MPG.

If you want ltr's per 100 divide ltr's used by km's then multiply answer by 100.

Keith


Title: Re: Fuel economy
Post by: Not Happy Jan on December 11, 2012, 07:05:58 AM
I see where I went wrong !
I did the calculation based on USgallons from google. 
Thanks..... Will peep you posted!
 


Title: Re: Fuel economy
Post by: Spinner on December 23, 2012, 01:17:36 AM
I've emailed you a couple of files that might help you.


Cheers


Title: Re: Fuel economy
Post by: Not Happy Jan on December 27, 2012, 10:02:54 PM
Hey Spinner
Sorry about the late reply but I didn't get any emails from you.
I would still be very keen to get them if you could resend them
Thanks
Nick


Title: Re: Fuel economy
Post by: Spinner on December 28, 2012, 11:43:27 AM
Resent


Title: Re: Fuel economy
Post by: Oggz on January 08, 2013, 09:29:03 PM
going from the last time I rode with you...how much lead you put into the soles of your shoes might play a small factor  :P


Title: Re: Fuel economy
Post by: Not Happy Jan on January 08, 2013, 10:03:50 PM
That's unfair Jamahl  :'(
I had to rush as you were on a time schedule! :D :D :D







Title: Re: Fuel economy
Post by: Dave Lakin (Davo Lako) on January 09, 2013, 03:28:09 PM
Good one Nick ... next thing will be that it's not your rubber outside my place on your way home from work  LOL ...


Title: Re: Fuel economy
Post by: Champ58FC on January 10, 2013, 05:03:47 PM
Hi,

Can someone advise me on how much lead replacement stuff to unleaded fuel for my FC ??

Cheers.


Title: Re: Fuel economy
Post by: Not Happy Jan on January 10, 2013, 08:39:38 PM
Hi Han
I think it's about 100ml per tank
There should be a ratio on the container
Nick


Title: Re: Fuel economy
Post by: Champ58FC on January 10, 2013, 11:26:52 PM
Hi Nick,

Thanks for that. Do you use fuel preservative if the car only runs say once a month or more? What lead replacement and fuel preservative do people recommend??

Ta  ;)