10 Steps to better fuel economy.

[feistl]

After seeing several "fuel economy" threads over the last few weeks i thought id post up a few tips for increasing fuel economy.

1. Driving Style - Pretty self explanatory. However, i can give a few tips to manual drivers....
In a manual commodore with EFI (Fuel injection), if your in gear with your foot off the clutch and accelerator and above 800rpm you will be using NO fuel. Thats right, when your slowing to the lights if you leave it in gear (and stay above 800rpm) you car will not use a single drop of fuel. This is because the ECU turns off the injectors till you put your foot down. So all those who put their foot on the clutch... your using more fuel.

2. Weight - Again, pretty obvious. Remove as much weight as possible, this will increase fuel economy.

3. Tire pressure. Pump your tyres up to recommended pressure... A deflated tyre will cause more rolling resistance and use more fuel. Also make sure your tyres are balanced and aligned. Not only will it give a smoother ride, use less fuel but it will also increase tyre life.

4. Service/Oil/Fuel + Air Filter change. - Its always a good idea to service your car, it saves money in the long run. Blocked filters will cause a (Small) increase in fuel usage.

5. Memcal Reprogramming - This makes a BIG difference. If you get yoru car reprogrammed to run on premium you'll save money (It costs more to fill but you'll go much further). Basically if your using premium with a standard memcal your wasting money. You need to have the ECU adjusted to get the most from premium. (NOTE - Once on premium, you cant run the occasional standard 91ron fuel... Its either always premium or always standard.

6. Cold Air Intake - Cold air is more dense, and gives more power. A Cold air intake sucks in cooler air from the front of the car resulting in better power, and much better response in peak hour traffic. Costs around $70 fitting depending where you go.

7. Spark Plugs/Leads/Coil packs - These are the main parts in the ignition sequence. As these age they provide less spark, which decreases performance and increase fuel usage. A New set of Spark Plugs ($30), Leads ($50), and MSD Coil Packs ($160) will see a marked improvement in power and economy.

8. Cleaning - Cleaning the throttle body and flushing injector cleaner through your engine is a cheap way to restore smoothness and power. It will also improve economy. Should cost you around $20 and a few hours labor.

9. Injectors - If you've got a VN-VP-VR with a buick engine, you can put later model injectors in for about $100. They tend to run smoother, give a tiny bit more power and use a little less fuel (really not much though)

10. Exhaust - Standard exhausts are pretty restrictive. Changing your exhaust (Either catback or a full system) will help the engine breathe easier. Again, will help fuel economy.

I have done all of the above (including servicing other parts) and i currently get 700kms per tank (8.5L per 100km) in my VR V6 Manual wagon on 98ron.

I highly recommend the memcal + CAI change

[POVRTY]

sh!t dude thats alot of ks for a vr?

[Chirpstr]

Good write up! I've done just about everything that you have there.
I get 9L/100km..has been 8.8L/100km or something around that before lol.
Using just regular unleaded.

[Cheap6]

Point #6 may be debatable - at part throttle (where most of us drive) the air in the manifold will be at less than atmospheric pressure and therefore less dense. Increasing the air density with a cold air intake is self-defeating. If you could vary the intake air temperature instantaneously, you could in theory run the engine unthrottled and eliminate the pumping losses associated with dragging air past the throttle plate and expanding it again.

There are other factors in that friction is greater due to the greater load on the rings, and that the engine may have the spark timing retarded due to knock.

Worth experimenting with a hot air intake I think.

LPG has some benefits here (other than the cheaper cost of the fuel) because of its (mostly) higher octane and that its already a gas and takes up some extra manifold volume.

Also, when reducing weight, rotating weight, like wheels will be of more benefit than the same weight removed from other items.

[feistl]

Point #6 may be debatable

Also, when reducing weight, rotating weight, like wheels will be of more benefit than the same weight removed from other items.

EDIT - Well after more research it appears im wrong...

"Marine power plants are frequently operated under varying atmospheric air temperature and humidity conditions. The effects of inlet air temperatures and humidity of marine furnaces such as incinerators and boilers thus attract much research interest. An industrial furnace incorporated with an automatic burner was employed to experimentally investigate the influences of the inlet air temperature and humidity on the emission characteristics. The inlet air humidity and temperature were adjusted using an air-conditioning machine to preset values before being admitted into the burner. ASTM No. 2D diesel oil was atomized, mixed with the inlet air and burned inside the industrial furnace. Eight small rectangular slots were cut on the upper side of the furnace to allow gas analyzer and thermocouple probes to be inserted into the furnace center to measure the axial variations in the gas temperature, burning efficiency and burning gas compositions such as NOx, SO2, CO. The experimental results show that the O2 and NOx emission concentrations decreased while the CO2 emission concentration and burning efficiency increased with either increasing inlet air humidity or temperature."

[V-ahhh]

maybe you should add changing your o2 sensors aswell?

[Chirpstr]

maybe you should add changing your o2 sensors aswell?

Yep for sure. I did mine and could feel/see the difference!

[immortality]

EDIT - Well after more research it appears im wrong...

"Marine power plants are frequently operated under varying atmospheric air temperature and humidity conditions. The effects of inlet air temperatures and humidity of marine furnaces such as incinerators and boilers thus attract much research interest. An industrial furnace incorporated with an automatic burner was employed to experimentally investigate the influences of the inlet air temperature and humidity on the emission characteristics. The inlet air humidity and temperature were adjusted using an air-conditioning machine to preset values before being admitted into the burner. ASTM No. 2D diesel oil was atomized, mixed with the inlet air and burned inside the industrial furnace. Eight small rectangular slots were cut on the upper side of the furnace to allow gas analyzer and thermocouple probes to be inserted into the furnace center to measure the axial variations in the gas temperature, burning efficiency and burning gas compositions such as NOx, SO2, CO. The experimental results show that the O2 and NOx emission concentrations decreased while the CO2 emission concentration and burning efficiency increased with either increasing inlet air humidity or temperature."

thats why late model cars have EGR. to reduce bad exhaust gases. still however not good for making power. basically coooler for power, hotter for economy

[greenfoam]

You want cold air in for sure. 800ks+ is well within reach on the highway of a good VR V6, maybe 850 with a manual, There's some VN manuals around the forums doing just under 7L per 100 and the VR is better, but that is about as lean as you want to go, well as far as I'm willing to push them anyway

[nbgreenp]

yeah thats all well and good. but i'm having trouble sourcing somewhere to get a remap for my vr. any sugestions. in syd, northen beaches if possible.