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PostPosted: Fri Jul 25, 2008 6:27 pm 
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Senior Swift Guru

Joined: Sun Sep 02, 2001 11:55 am
Posts: 2595
Location: Calgary, Alberta
Until the past few months, my best tank in 8 years of driving Swifts (or any of the other 1.0L, turbo, non-turbo, 16 v sohc, 8 valve 4 cyl) was around 600km in one of my GTs on somewhere under 30L. It was going through the mountains, and I was heading to a lower elevation.

That 600km tank always seemed like a mythical one-time error in all my years of driving these cars. My typical 30 litre fill in the any of them got me around 400-450km no matter how ‘nice’ I seemed to drive and with turbo or without turbo.

And yet now, I can consistently approach 50mpg in my Swift doing the speed limit, without any kill switches, truck drafting, engine off coasting, or magical fuel magnets to align the red dots and blue in my fuel stream for better mileage.

So how can it happen?

The simplest way to look at it would be to say that I’m simply following what would be your typical OE manufacturer published ways to get better mileage (plus a few hacks).

Avoid ‘jack-rabbit’ starts
- Avoid quickly pressing down the accelerator (or jack-rabbit starts) – Why? Acceleration enrichment – everytime the ECU encounters a certain amount of throttle position change. It injects extra fuel for what is called acceleration enrichment for smoother response/more power. Modern econocars are starting to take this away, but most performance cars still use it.
- Be smooth, the ECU wants to go out of closed loop mode on a GT very easily. You want it to stay in closed loop and be close to stoich 14.7:1.
- Avoid huge throttle openings (15-20% max). Sure volumetric efficiency will be higher with more throttle opening. However, the power enrichment and fuel consumption from more throttle opening kills that gain in VE. As a guide, wherever your foot is on the throttle to keep the car at a steady 100km/h, that’s the max amount of throttle opening you should use all the time (it feels like 3% on the pedal for a while).
- MAF, TPS, coolant temp, etc.. all play a role in making things rich with the kind of throttle opening you desire to have. This stock tune may actually negate the benefits of pulse-glide techniques, etc.. More than 20-30% throttle may be the max before it starts going rich. Take the amount of throttle you use to cruise on the hwy, and apply that to your acceleration as it is basically the max.
- Be in the lowest gear you can at lowest speed (manufacturers these days seem to recommend just above lugging speed if your cruising, and slightly above that if you are accelerating between gears). Shifting around 2400-2500rpm is a good range. A little less if you’re not going to hold anyone up.
- Don’t idle for a long time. Do your crap, buckle up, swap out your ROFL ROFL cds, and then start the car and drive.
- If you see that you have no one behind you and you can try to slow down before a light and keep some momentum, then do it.
- Make less trips or do more on one trip
- Make sure you have proper alignment
- Make sure all sensors are functioning properly
- Synthetic may give you something
- Sure weight is important, but the manual for my Tribute approximate 1mpg for every 400lbs (steady state only… accelerating at same pace, a whole other story)
- Don’t drive the automatic. GTs shouldn’t have an automatic anyway but they suck power all the time. Sell the car, buy something else.
- Have a manual? There is no reason that you can’t leave the car in gear, put your foot on the clutch and coast the odd time. Also there is no reason you can’t leave it in gear and coast to a stop at a light. Guys behind you won’t tolerate coasting to a stop light, but using the gears usually isn’t bad.
- Vehicle tune-up – plugs, wires, tires inflated, all those wonderful things that you should have done anyway.
- If you want a GT as an economical car, own it as an econo car and consider that it no longer revs to 7500rpms. Never. Don’t even do it. (disclaimer - I still have the odd weak moment that drops me a mpg here and there)



I live in Redneck central in Alberta. 9 out of 10 people own trucks and guns. Don’t cock-block/Ukrainian road block other cars behind you. Don’t drive in the shoulder to let people pass and throw rocks at their car. Don’t drive on the ass of a large truck and kill HIS gas mileage by a few mpgs (it angers them and if they put on their rear light to blind you, good on ‘em). However, you can pick the lane with a truck in it or pick the lane with the slower car in it, and go the speed limits or a little above in the city. I’m still driving around people who are unbearably slow, or who don’t understand the speed limit is the minimum to not get run over.


Onto some other ideas/explanations to help squeak out that mileage...

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 Post subject: Some problems
PostPosted: Fri Jul 25, 2008 6:33 pm 
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Joined: Sun Sep 02, 2001 11:55 am
Posts: 2595
Location: Calgary, Alberta
Some problems and a shortened list to what kinds of things typically give the GT such crap mileage in comparison to the hypermiling 3 cyls?


- Your mods and how they effect the readings from the MAF. As good as this system is or is not, it is extremely sensitive to how air is going over it. Piggy-backs like Split sec and SAFC only change the voltage by 10-25mV at a time to try and get the a/f you want. When you put a bigger intake pipe, smaller intake pipe, different filter, cold air intake.. all of these mods have the potential to make much more than a few mV difference. This will quickly mess up your a/f ratio, how quickly the GT ecu goes rich, how rich it will go WOT, etc.. This must be learned to be used as an advantage instead of a negative.
- Cold start enrichment. The GT ECU determines how long it will warm up, based on initial temperature (not all ecus like this). Over 20-30C the warmup time is quite short. At -20C, the car won’t go closed loop for 3-4minutes. It also won’t cut fuel while decelerating during warm up, etc.. And, if you shut the car off and come back in 5-10minutes, it’s cooled off enough to stay out of closed loop again.
- Cosed loop mode is pretty weak on the GT and it seems to have a 100 reasons to add fuel to it’s equation to ruin that nice stoich you are after..

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PostPosted: Fri Jul 25, 2008 6:45 pm 
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Joined: Sun Sep 02, 2001 11:55 am
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Location: Calgary, Alberta
So how to get around some of the problems above? The idea is to find ways to reduce the amount that the factory ECU dumps in extra fuel at low to mid throttle openings. Modern econoboxes are smart enough to just about never go out of stoich. You can touch the throttle, ½ throttle, ¾ throttle, ¼ throttle, quickly open the accelerator, and they just about always stay 14.7:1 if it’s a true econobox.

The GT as mentioned, comes up with a lot of reasons to go into ‘power’ mode and add fuel to stoich whenever it can. In order to reduce the effects of this, there are some tips that you can play around with. It will still be very mod specific, location specific (alititude) etc.. but they are things you should look into.

- Aim for a larger intake pipe between the MAF and TB. 3” pipe is easily a good starting point. The stock ECU runs too rich, we want to lean it out by decreasing velocity on other side of MAF. Don’t believe me? I can make my GT just about stall with a cold air intake, small intake pipe because it is so rich or I can make it run so lean that it barely runs with a big pipe, and no air filter on the other side. All this is due mostly to the change in airflow through the MAF. And our ECU isn’t quite good enough at adapting with inadequate long/short term fuel adjustments. Also WOT, big pipe will lean out the overly rich stock a/f and may make a couple of hp from this.
- Don’t do a ram air intake – although good in theory, it’s REALLY bad with the stock MAF. It will force air over the MAF, and make it think there is need for more fuel than there is at any reasonable speed. I have datalogs that can show just how rich a CAI can be (there is a post on here as well)… in my experience it has always consumed more fuel, and made the car slower in the ¼ do the 10:1 a/f the car ends up seeing.
- Have a less restrictive inlet filter.
- Think about a larger TB - to allow a little more air in at the same throttle opening. Will require some other mods. If you nix the idle speed control, you can get rid of the annoying 2500rpm starts these cars do.
- Keep your TPS adjusted properly. TPS can easily be adjusted 0.1V-0.4V output with throttle basically closed. This will effect the starting point in ECU for lookup table. Less, should mean less fuel.
- Play with timing adjustment. Maybe your car will get better gas mileage with more, maybe with less. Treat it individually and don’t rely on the internet. If you’re at Sea-level, and I’m at 4000ft ASL, it matters.
- Decrease resistance from coolant temp sensor to get it out of cold start enrichment sooner. Even then, CHECK the resistance on your stock sensor. I’ve had them read 10000 ohms when cold. This means my ECU thought it was -20 and it stayed pig rich for 4 minutes every time I did a cold start. If you can’t find a GT one, use the 3 cylinder one. They are pretty much the same (minus connectors) and I found a ton that read properly in the wrecker and they were free (I asked, I didn’t steal it).

And here’s the biggest one again -

Adjust your ATTITUDE! “It’s so boring, I hate this, stupid truck going slow, what the hell is wrong with this guy, I can’t do that, it’s not practical, I’d rather pay the extra $5-$10, yadada” I’ve heard all of the excuses, used them all myself, and had just as much time above the speed limit as anyone here…. But, this thread is not for these sentiments or excuses.

The proper ATTITUDE may sound retarded and it will go against everything testosterone, but make it fun, and make it something you mentally want… you should be telling yourself things like “Sweet a large truck in that lane at the stop light. I’m going to accelerate behind him so I can accelerate slowly and people think I’m waiting for the truck.” “GREAT! That guy ahead is going slower than I am, and just came into my lane. I can coast up to him and cruise nicely” “Look at that idiot… he just wasted a gallon of gas passing me at 130km/h. I’m so better than him”

It’s all perception, fine tweaks, and your right foot. The platform is there and yes, 50mpg is easily possible in a GT using normal driving techniques.

EOC, pulse and glide, lower speed limits.... the sky would nearly be the limit. I'm trying to build the patience to try some 80km/h side roads to work, but I'm not there myself.

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PostPosted: Fri Jul 25, 2008 6:52 pm 
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Senior Swift Guru

Joined: Sun Sep 02, 2001 11:55 am
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Location: Calgary, Alberta
If you can keep below 70km/h even, you should theoretically be able to hit some big numbers.

Image

Again with EOC, P&G, you could be famous... or well, at least get even more MPGs.

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PostPosted: Fri Jul 25, 2008 7:24 pm 
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Joined: Tue Apr 29, 2008 8:06 pm
Posts: 1445
Location: Atlanta GA 30052
whattheeee wrote:
... magical fuel magnets to align the red dots and blue in my fuel stream for better mileage.

Good posting. The GT can get much better economy than the average crap being sold today. my magnet instructions show yellow and green fuel dots! How do i know which gas to buy?

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the time i mispent in my youth

daily driver: red 1991 Metro 3cyl 5sp, roof rack, 8 degree advance,
got 61 mpg combined on 14" tires but i prefer 12"

completed frame up restoration: black 1994 Swift GT 5sp -- like new ! 45mpg


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PostPosted: Fri Jul 25, 2008 7:59 pm 
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Joined: Tue Oct 24, 2006 3:09 pm
Posts: 4998
Location: Palm Springs: Too hot from June to Oct.!
whattheeee wrote:
Don’t drive the automatic. GTs shouldn’t have an automatic anyway but they suck power all the time. Sell the car, buy something else.


Yep, sell it to me.
My wife would love it.
She prefers an automatic.

I can easily hit 44 mpg in the 89 GTi by driving it easy, and not going over 55 mph.
Haven't really tried the 92 GT yet, but it has better compression numbers.

But they are such FUN to drive, it's hard to keep my foot out of it. :!: :!: :!:

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DIY Broken Bolt Removal: viewtopic.php?f=22&t=41042
DIY Clutch Adjustment: viewtopic.php?f=9&t=48281
DIY Wheel Bearings: viewtopic.php?f=2&t=29003
DIY Shocks: viewtopic.php?f=10&t=45483
DIY Wheel Align: viewtopic.php?f=2&t=42479
Once you get the cars dialed-in (compression, leaks, bearings, alignment, brakes) swap in new rubber and glass, you've got something which should last for years!


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PostPosted: Wed Aug 06, 2008 1:00 pm 
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Senior Swift Guru

Joined: Sun Sep 02, 2001 11:55 am
Posts: 2595
Location: Calgary, Alberta
yeah, I'm just not quite as entertained as I used to be with these cars. I guess I shouldn't say you can't go normal speed on the highway. I've averaged over 50mpg for around 2000kms now, with half my drive around 65-70mph (few hundred kms at 80mph).

I have nothing against autos, it's just not going to get you 50mpg in a Swift (maybe driving really slow).

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