Mods and recommendations for fuel efficiency

[frogsta]

I know this is probably asked a lot, but wondering on any stories on how much fuel efficiency I can expect to gain (If driving nicely :P) with a CAI, and possibly pacemakers and a high flow exhaust?
Also, what's a good store to go to in WA?

[zapper-l67]

Is it a 6 or 8 ?

[frogsta]

3.8L V6, VS so an Ecotech if that makes any difference. It does have gas, but for some reason it just keeps stalling when I try on gas.

[The_Doctor]

A simple answer, NONE. I put a CAI on my SSV Redline and it sounds so mean when I plant the foot now my fuel economy is about 20l/ 100km, before it was 14

[frogsta]

Hahah I know I'll probably get carried away with it, but if I drive nicely I'd assume it's better for my fuel lolz, of course if I floor it it'd get more air etc. and use more fuel I'm aware of that though

[Robb]

The amount of fuel saving that can be made by certain mods will never return the savings to ever pay for the mods, as the savings in fuel will be so small.
Also if you are concerned about fuel, aftermarket extractors and a cat back will reduce fuel efficiency as a result of loss of torque down low (2.25" cat back will minimises this)
I'm not saying don't mod your car, just that I wouldn't be going out to mod my car because I want my car to be more fuel efficient.

[ucwepn]

I believe you can buy a memcal that leans out the lean cruise even more, run the correct tyre pressures and don't carry excess weight in your car. extractors and exhausts don't really save fuel and a cold air intake puts more air into the engine (colder air is more dense) so the computer has to fix the mixture by adding more fuel anyway.

[Scrubmonk]

What sort of ecomony are you currently getting for what sort of driving? An ecotec should be good for about 8-9L/100Kms country driving on 91RON.
The most obviously solution is to get your gas issue sorted out, so regardless of the economy, it will be cheaper to run.
As far as cheaper add ons, you could try a K&N type air filter to let it breathe a bit easier, a lower temp thermostat to keep the engine running cooler (and more efficient), and I have heard good things about the plenum spacers from MACE but never tried one myself.
In my experience a good exhaust system will also improve economy a bit and won't noticably sacrifice torque so long as it is kept to a sensible size, but with an improved note it is also likely the car will get driven harder as well.

[MR_JORDZ]

I believe you can buy a memcal that leans out the lean cruise even more, run the correct tyre pressures and don't carry excess weight in your car. extractors and exhausts don't really save fuel and a cold air intake puts more air into the engine (colder air is more dense) so the computer has to fix the mixture by adding more fuel anyway.

Agree on this^

[Not_An_Abba_Fan]

Extractors and exhaust actually do improve fuel economy when cruising. If you do a lot of short stop start trips, then no they don't. Freeway driving, expect about a 10% saving on fuel as there is less restriction in the exhaust.

Extractors on their own with the stock exhaust will give a better improvement than doing the exhaust as well. It comes down to money spent versus money saved. Most of the time, just keeping the car serviced and the tyre pressures actually higher than recommended will save more fuel. I have always run a minimum of 40psi is stock sized tyres and the fuel saving has always been noticeable.

Getting a tuned memcal will also improve economy.

But as I said, you can spend a lot to achieve a little so if economy is your goal, maybe a different choice of car would have been better.

[frogsta]

No problems thanks guys, it was rooted from an argument with a friend hah, but yeah, I'm looking to mod in general anyways, though obviously say a higher diff ratio isn't going to be as good for my fuel, etc

[Not_An_Abba_Fan]

If you want a good deal on the exhaust side of things and want to come for a drive to Bunbury, I can do your extractors and system at a really good price.

[wildeagle44]

I've had terrible fuel economy since i got the car 2 years ago, I re-earthed the oxygen sensors and have seen an improvement in fuel consumption. Its a known issue with the vs as it was the 1st to use a 4 wire 02 sensor (as opposed to a 2 wire) with a heater built in. Might be worth a look. Fairly simple and cost ya next to nothing.

[James39]

I've had terrible fuel economy since i got the car 2 years ago, I re-earthed the oxygen sensors and have seen an improvement in fuel consumption. Its a known issue with the vs as it was the 1st to use a 4 wire 02 sensor (as opposed to a 2 wire) with a heater built in. Might be worth a look. Fairly simple and cost ya next to nothing.

It is funny that mine is the four wire and is all original and has no problems apart from one time there was a conection problem at the plug for one of the sensors...

[peckzz]

A simple answer, NONE. I put a CAI on my SSV Redline and it sounds so mean when I plant the foot now my fuel economy is about 20l/ 100km, before it was 14

haha my fuel economy is 14 litres of premium to the 100 kms lol, with my mrs driving on open road sitting on 100 km/h, 1900 rpm or something

mods are as is \/ \/ \/

[Brett_jjj]

It is funny that mine is the four wire and is all original and has no problems apart from one time there was a conection problem at the plug for one of the sensors...

My VS is also one of the first VS's that use the 4 wire 02 sensors, and Ive never had a problem with fuel economy or bad 02 sensor readings, and have not done the sensor wire fix, the only time Ive had problems with 02 sensor readings etc when I tried to run a tune that Id done on a later release of the VS memcal. This totally stuffed up my 02 sensor readings and fuel economy, and the short and long fuel trims were way out. I tried the earth fix on the 02 sensor wires and there was no difference. I ended up doing the tune using my old memcal version as the base for the tune, and I had no more problems with 02 sensor readings or fuel economy or fuel trims. The later VS's dont seem to suffer from this problem and can use pretty much any of the VS memcal versions. Most people who sell tunes will use the latest memcal version as the base for the tune. Ive also talked to other people who have early 4 wire VS's and have ran into the same problems when trying to run the later memcal versions.

[Robb]

Hmmmmmmm
My 95 VS has two wire O2 sensors.
So very early VS's had two wire O2 sensors?
And I recently ordered a tune from MACE, hopefully it is tuned for the early two wire VS commodores so I don't run into issues like you speak of Brett

[ephect]

yea the first vs's had 2 wire then they moved to 4 wire.. i only found this out after i did the how to earthing the o2 sensors thread.

as previous posts, keep tyre pressures up, carry minimal stuff in the car, and service and maintain the car. wheel bearings may also be close to being shot, draging brake shoes/pads.

[bpefi]

I have a vs / trans in a Hilux ute - I gave up on getting fuel economy from the std oxygen sensors on petrol - did all the earth fixes etc - I run it on LPG & tune it with a Lambda meter - for some reason the oxygen sensors read lean when its still rich - result poor fuel economy.

I don't know what it is but it seems to be on later combinations of Memcal to computer - I run a dual map memcal - one tune map for petrol - one for LPG - which works so much better than trying to run it with a Petrol only map.

I also run an Airod variable mixer - the difference between a std ring mixer & one of these is awesome - it just drives like its on petrol. They are not available new anymore you might have to look through the wreckers - though you will probably have to go with a Blos CV variable mixer - There are many posts on these on here somewhere & available at times on Ebay.

I use Pulstar spark plugs which also makes a noticeable difference to power & fuel economy with much less backfire problems.

I talked to Mobil & dropped to a thinner engine oil on my 2.0 L Hilux to a 0W40 full synthetic from a 20W50 Mineral oil & picked up a lot of power & huge increase in fuel economy on that vehicle - I also fitted the Pulstar plugs to that & from then on I got over 1000k per tank (128L useable) from roughly 660 K per tank.

I have not changed the VS over as yet as I just did the motor up & set it up specifically for LPG with high comp pistons / double row timing chain etc & I have not run it in as yet. But looking forward to what will happen there.

Running like it is I doubt that anyone would see the difference between petrol & LPG on the road & empty I think it would kill a std VS on LPG & thats before I did the engine up ... its better than ever now without the balance shaft & the high comp pistons - I run a 3.7 ratio rear end & it just flies yet I get 13 L per 100 the highway & 15 L per hundred around town - so I cant complain about that at all.


Run good tyres & keep them pumped up well - make sure the wheel alignment is right (this can cause huge losses in fuel economy) make sure that your brakes are not dragging. Take any wind restrictions off the car (roof racks etc) & if you want to go anal - polish your car LOL - You could probably spend some money & get twin high flow cats possibly for top end anyway - I still have the std manifolds & exhaust - I dont know what difference that would make but .... for me but its custom extractors - so thats a bit scary. I have tried to make the most difference for the least amount of money & I have won on both counts so far & very happy - when I first drove it home after the mechanics fitted the LPG I just couldn't believe it - it was like a pig & now a couple of minor things & its transformed.

[frogsta]

If you want a good deal on the exhaust side of things and want to come for a drive to Bunbury, I can do your extractors and system at a really good price.

I'm quite rough on money at the moment only got about $900 but need Christmas stuff, but how much were you looking for? I go on holiday soon too, so I won't have money anytime soon but yeah it helps I'm just trying to budget and stuff now. Gonna go to an LPG specialist too.

[James39]

haha my fuel economy is 14 litres of premium to the 100 kms lol, with my mrs driving on open road sitting on 100 km/h, 1900 rpm or something

mods are as is \/ \/ \/

I get around 9 to 10 litres per 100 k's on the freeway sitting on 110...

Just installed a big mouth air intake and soon to add pacemaker extractors... Hopefully my fuel usage will not increase

[Drawnnite]

it might help if you say the L/100 you get so we know if your getting it good average or bad =P

anyway in my v6 man vs ute i can get about 8L per 100 on the freeway at 80/100/110 (speed varies)
and about 9-11L per 100 for traffic/town driving.
only has the S/C CAI and 12mm Mace Plenum and 12mm Mace Manifold spacers.


however intersting fact. Dimple your car like a golfball and it will better the fuel economy =P

[frogsta]

Golfball also goes faster ahah gotta love Mythbusters. I'll need to fully fill up my tank and remember to take a reading sometime.

[Krilnik]

I got about a litre more per 100ks just from changing the fuel filter.

[hako]

The best aid to economy is a driver who operates his vehicle efficiently. There are many driving techniques which achieve an increase in fuel economy yet can make driving more enjoyable not just for you but your passengers. They can cost nothing to adopt. Back a few years the fuel companies used to run Economy Trials - they involved completely standard vehicles which had to drive from (say) Sydney to Melbourne in 10 hours. The fuel efficiencies they achieved were quite amazing and they were achieved purely through driving technique. This can cost nothing.