Welcome to the Australian Ford Forums forum.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and inserts advertising. By joining our free community you will have access to post topics, communicate privately with other members, respond to polls, upload content and access many other special features without post based advertising banners. Registration is simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact us.

Please Note: All new registrations go through a manual approval queue to keep spammers out. This is checked twice each day so there will be a delay before your registration is activated.

Go Back   Australian Ford Forums > Ford Australia Vehicles > Small and Mid Sized Cars > Focus

Reply
 
Thread Tools Display Modes
Old 23-07-2008, 02:39 PM   #1
yogi_bear_68
Starter Motor
 
Join Date: Jul 2008
Posts: 4
Default TDCI high rpm in 6th gear

Has anyone noticed the diff ratio for gear 5 & 6 in the Focus TDCI may not be correct?
My car does a fraction over 2000rpm in 6th gear at 110km/h.
According to the specs on the Ford website, the car should be doing 1850rpm.

I've worked it out using the following:
Gear ratio .71
Drive ratio 2.85
Tyre circumfrence 2.000566m ( based on 17" 205/50)
RPM is speed in km per hour /3.6/wheel circumfrence * gear ratio * drive ratio * 60
RPM = 110 / 3.6 / 2.000566 * 0.71 * 2.85 * 60
RPM = 1854

I'm wondering if that's why my fuel economy is usually around 6l/100km even if I drive like a grandma.
eg. Trip from Melbourne to Mt Gambier sitting on cruise control at 100km/h...fuel economy was 5.9
That's a long way from the 'official' fuel economy of 5.6

yogi_bear_68 is offline   Reply With Quote Multi-Quote with this Post
Old 23-07-2008, 02:52 PM   #2
photn
AFF Post NAZI
 
photn's Avatar
 
Join Date: Mar 2006
Location: Albury
Posts: 3,634
Default

How old is the car and how many KM does it have.
__________________
"Its not always about power, The car has to handle Beautifully"

photn is offline   Reply With Quote Multi-Quote with this Post
Old 23-07-2008, 03:08 PM   #3
yogi_bear_68
Starter Motor
 
Join Date: Jul 2008
Posts: 4
Default

2008 model - 4600km on it.
yogi_bear_68 is offline   Reply With Quote Multi-Quote with this Post
Old 23-07-2008, 06:40 PM   #4
Turbodiesel
Torquer
 
Turbodiesel's Avatar
 
Join Date: Jul 2007
Posts: 393
Default

That is correct, but I would hardly consider that as "High RPM". I consistently get around 4.9l/100km on my work runs which is mostly highway but is quite hilly in some areas and I drive normally.

Fuel economy doesn't depend solely on RPM, there other factors such as terrain, wind, tyre pressure, air con etc but that does seem high.

Next time you're cruising, reset the economy and it'll give you an instant readout.
__________________

2007 LT Focus TDCi S
Bluefin Remap - K&N Apollo CAI - 2.5" Turbo-back Straight Pipe - 24mm Rear Sway bar - LT Zetec Bodykit - Black Projector Head Lights - LED Tail lights - DMB Overlays - Alloy Pedals - Scuff Plates - Sports Gear Knob - LV XR5 Springs - LV XR5 Wheels - Pirelli P-Zero Nero
Turbodiesel is offline   Reply With Quote Multi-Quote with this Post
Old 23-07-2008, 10:54 PM   #5
photn
AFF Post NAZI
 
photn's Avatar
 
Join Date: Mar 2006
Location: Albury
Posts: 3,634
Default

Quote:
Originally Posted by yogi_bear_68
2008 model - 4600km on it.
wait till 7000 and the car should be running sweet and the car should be bedded in.
__________________
"Its not always about power, The car has to handle Beautifully"

photn is offline   Reply With Quote Multi-Quote with this Post
Old 23-07-2008, 11:16 PM   #6
Kariharnett
Lil Henry
 
Kariharnett's Avatar
 
Join Date: Dec 2007
Location: Townsville Nth Queensland
Posts: 168
Default

5.9ltr/100km is pretty good. cruise control uses more fuel then manually driving the car too as it is constantly keeping the speed especially on small inclines and wind. wheny our driving the car yourself you tend to say go from 100 to 90 and gradually up to 100 again. i noticed my car was alot more fuel effecient around 7000km's.
Kariharnett is offline   Reply With Quote Multi-Quote with this Post
Old 23-07-2008, 11:16 PM   #7
AnthonyTDCi
Focus TDCi
 
AnthonyTDCi's Avatar
 
Join Date: May 2008
Location: Melbourne
Posts: 192
Default

my rpm's are the same @ 110kmh.

turbodiesel is right....a heavy foot with low rpms can result in bad economy.

6lts isnt bad....but you can get better. i consistantly get between 5-5.7l/100 with fart city driving
AnthonyTDCi is offline   Reply With Quote Multi-Quote with this Post
Old 24-07-2008, 09:14 AM   #8
NO2
Old Man
 
Join Date: Oct 2007
Posts: 44
Default

Yeah with 18,000k I am getting consistently 5.3 -5.6l/100. That is driving around the sunshine coast and to Bris.
I have managed to get 4.9l/100k driving from Bris back to the coast by keeping at 100km per hr.
NO2 is offline   Reply With Quote Multi-Quote with this Post
Old 24-07-2008, 11:30 AM   #9
yogi_bear_68
Starter Motor
 
Join Date: Jul 2008
Posts: 4
Default

Thanks for the replies everyone. I didn't really mean to complain about the fuel economy ( which is still pretty good), but comment on the diff ratio for 5th & 6th.

Using the specs from Ford I was expecting to run at 1850rpm at 110km/h, my car does 2050rpm. Just wondering why that figure might be different.

I'll experiment with my driving technique & use of the cruise control ( I am used to a v6 manual Commodore!) and see how it goes. I have averaged 5.3l/100km the last 2 days driving to work on the Westgate Fwy. Pretty impressive!
yogi_bear_68 is offline   Reply With Quote Multi-Quote with this Post
Old 12-08-2008, 12:52 PM   #10
wizamc
Regular Member
 
Join Date: Sep 2007
Posts: 32
Default

Hey yogi

The RPM your getting is pretty typical for that sort of speed, and I understand why you question it, as I expected lower RPM myself when I started to drive my car, and after 55,000kms its no different now. I was glad to hear your economy was better though, as I normally get between 5.1-5.3l/100km and thats driving from Wollongong to Western Sydney (it bolts up Mount Ousley in 6th...glorious).

I wouldn't worry too much about cruise though. It took a while but you become tuned to your car after a while, and can tell the difference in driving speed and tend to be able to hang steady, that it makes no difference if your using cruise or not.

Enjoy the drive... I love it
wizamc is offline   Reply With Quote Multi-Quote with this Post
Reply


Forum Jump


All times are GMT +11. The time now is 09:25 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Other than what is legally copyrighted by the respective owners, this site is copyright www.fordforums.com.au
Positive SSL