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secret to better fuel economy?

Posted: Tue Sep 02, 2008 8:29 am
by loki
I seem to have stumbled across a real fuel saver, for me at least. The bolt that holds the throttle position sensor or kick down linkage fell out a couple weeks ago and I haven't gotten around to replacing it, and now I don't think I'm going to, I haven't gone through a full tank yet (yes jumping the gun a little) but I'm looking like I'll get about 100km more from this tank than ever before. I just have to kick it down my self if needed with the O/D button or shifting into second (very rare). Before anyone jumps down my throat I'm not advising anyone to go do this them selves but maybe adjusting it to not kick down so easily might be a good place to start.

anyways, I'll keep you guys posted on how it goes.

Re: secret to better fuel economy?

Posted: Tue Sep 02, 2008 9:46 am
by Green1
now that you bring it up... My kick-down is definitely happening in the wrong place (often kicks down to a rev that is over red-line, and even when it doesn't, I kick down to LESS power because it's outside the power band of the engine), so I want to adjust this, however I'm affraid I don't have a clue what to look for or where... any pointers?

Re: secret to better fuel economy?

Posted: Tue Sep 02, 2008 11:07 am
by Jester
That's definitely something to look at. In general I think they are adjusted for performance rather than economy...I'll take the economy, thanks :)

I got another tip: lighten the load as much as possible.
Since I had to remove ll the seats in the back for work, I'm getting 1/2L per 100km better economy.

Also keeping the RPMs down does wonders. Let them pass you! :-D
these older Diesels don't like to be revved up too much anyways...

Re: secret to better fuel economy?

Posted: Tue Sep 02, 2008 12:10 pm
by jessef
Low RPM's = heavenly mpg on the 2.5's 8-)

Re: secret to better fuel economy?

Posted: Tue Sep 02, 2008 12:48 pm
by BCDelica
Green1 wrote:now that you bring it up... My kick-down is definitely happening in the wrong place (often kicks down to a rev that is over red-line, and even when it doesn't, I kick down to LESS power because it's outside the power band of the engine), so I want to adjust this, however I'm affraid I don't have a clue what to look for or where... any pointers?
There are two flat nuts near the IP, on either side of a bracket, that allow you to adjust the kick down cable tension, and shift down points. But instead of providing a confusing new set of instructions, search the UK forum and you will find a detailed step by step on doing so.

Re: secret to better fuel economy?

Posted: Tue Sep 02, 2008 1:45 pm
by mararmeisto
Simple: less right foot.

Translated: lower RPMs.

Re: secret to better fuel economy?

Posted: Tue Sep 02, 2008 5:41 pm
by The Pinkfingers
mararmeisto wrote:Simple: less right foot.

Translated: lower RPMs.
Agreed. I try to keep it under 2500 rpms all the time - maybe up to 3000 on longer hills (unfortunately there are many of these in North Van, but at least I also get to go down them as well).

Re: secret to better fuel economy?

Posted: Tue Sep 02, 2008 7:05 pm
by loki
mararmeisto wrote:Simple: less right foot.

Translated: lower RPMs.
true, but sometimes you need a little extra power for climbing a hill or some such and you just cross over that threshold and BAM it kicks down and your up around 4K rpm let off the pedal and there isn't enough power you end up shifting back and forth running high rpms or slowing down WAY to much. I find it easier to maintain the speeds I want and not get high rpms with my new manual kick down :). I will post back after I finish off this tank but I don't drive much (5 minute bike ride to work so I have no excuses)

Re: secret to better fuel economy?

Posted: Wed Sep 03, 2008 12:26 pm
by Schwa
Mine was adjusted terribly when I got the van, it would rev up to 4500 RPM easily with only moderate acceleration, I adjusted that cable and it now works great... the indication of a correctly adjusted kickdown is if it shifts into OD at 60km/hr under light-medium acceleration.

Re: secret to better fuel economy?

Posted: Wed Sep 03, 2008 1:08 pm
by DelicaMark
I think a boost gauge is a great way to see how much fuel you are using. It gives you a much better idea of the actual load on the engine rather then just watching the revs. I have noticed a lot of the time that when I am running a little higher revs I can ease off a little on the throttle (but still not dropping a gear) and the boost drops, which to me means less fuel being burned.

-Mark

Re: secret to better fuel economy?

Posted: Wed Sep 03, 2008 1:21 pm
by mararmeisto
loki wrote:
mararmeisto wrote:Simple: less right foot.

Translated: lower RPMs.
true, but sometimes you need a little extra power for climbing a hill or some such...
Use more cowbell.

Re: secret to better fuel economy?

Posted: Wed Sep 03, 2008 2:22 pm
by FalcoColumbarius
Gene....I gotta fever ~ and the only prescription is more cowbell! :mrgreen: Explore the space, Gene..... I mean really......... explore the space!

As far as North Van is concerned: The only area where I Exceed three grand is if I'm trying to get on the highway, east bound, at Lonsdale, especially from St. George's and only because I want to get up to light speed with the traffic. BUT... there are other routes for getting in and out of North Van. I had a 3/4 tonne chevy van that had a 305 V8 in her..... you really get to know the neighbourhood infrastructure well when you are driving a 305 V8. Enjoy the journey... take a little more time. Also I might add that higher RPMs in the short term lead to lower RPMs in the long term, i.e.; it is better to spend five seconds at 3000 RPM then ride at 2000 that to spend minutes at 2700 RPM thinking you are saving fuel :cry: .

Falco.

Re: secret to better fuel economy?

Posted: Wed Sep 03, 2008 4:08 pm
by Profister
For those thinking that low rpm's are always = lower fuel consumption I recommend reading this: http://www.physicsforums.com/showthread.php?t=165455
Also with my recent trip to Kamloops and back on Coquihalla watching my EGT gauge I was shocked with the temperature readings while climbing on 4th at 65-70 km/h, 1400 F :shock: vs. usual 500 F. After that I was shifting down to 3rd getting higher revs and keeping temperature under 1000 F.
The conclusion: be careful with "saving" fuel on low revs under load.

Re: secret to better fuel economy?

Posted: Wed Sep 03, 2008 10:58 pm
by delicat
Good point Profister, that's how I kept my old VW alive, revving the s**t out of them while climbing! (not lugging anyway... :-D ) It keeps the fan blasting cool air to those engines, happy engines.

Re: secret to better fuel economy?

Posted: Thu Sep 04, 2008 7:04 pm
by ccautos
mararmeisto wrote:Simple: less right foot.

Translated: lower RPMs.
Damn , and there was me thinking my throttle was an on/off switch !!!!