Fuel mileage think tank thread

[IndyIan]

We get cars from everywhere, for example, a toyota Echo sedan is made somewhere in N.A. but the hatchback was brought over from Japan. I think all the late 90's mazda 626's with V6's were brought over from japan but the 4 cyl ones were built in detroit.

Here's some information on OBDII, there is some information on the different protocols, maybe it will help. OBD-II - On-Board Diagnostic System
Ian

[*Kiwi]

I was able to get my OBD-II cable to work on my '04 Japanese-made diesel GV by rewiring the plug slightly on advice from another owner in the UK. The cable I have was intended for VW.

In a nutshell, jumper the K- and L- lines together.

You'll need to google a pinout for the plug but it worked fine for me.

[murcod]

Originally Posted by *Kiwi

I was able to get my OBD-II cable to work on my '04 Japanese-made diesel GV by rewiring the plug slightly on advice from another owner in the UK. The cable I have was intended for VW.

In a nutshell, jumper the K- and L- lines together.

You'll need to google a pinout for the plug but it worked fine for me.

Thanks for the info Kiwi, but I'm a bit hesitant to jumper the two incase something goes up in smoke? I've just spent about an hour Googling for info on jumpering/ joining the K and L lines with no luck.

[murcod]

OK, I've just been out and checked what pins are "populated" in my OBDII connector.

All I've got are pins 4,5,7,9,16 - which seems to indicate I might have a ISO OBDII connection in my Aussie spec 2004 XL-7 (H27 engine)?

There's certainly no "L line" to short as it's pin 15 from what I've found?

OBDII pinout, Signal Assingments
1. -
2. Bus positive Line of SAE-J1850
3. -
4. Chassis ground
5. Signal ground
6. CAN high (ISO 15765-4 and SAE-J2234)
7. K line of ISO 9141-2 and ISO 14230-4
8. -
9. -
10. Bus negative Line of SAE-J1850
11. -
12. -
13. -
14. CAN low (ISO 15765-4 and SAE-J2234)
15. L line of ISO 9141-2 and ISO 14230-4
16. Battery voltage

The assignment of unspecified pins is left to the vehicle manufacturer's discretion.

https://www.scantool.net/support/ind...icleid=3&nav=0

[*Kiwi]

My interface socket has a 15 in addition.

The adapter box/plug I have, labeled "ISO 9141" has 4, 7, 15, and 16 only. Internally I disconnected the L (15) pin from the PCB and tied that pin to the existing K (7). It seems the 15 "wakes up" the interface and subsequently is not needed.

[murcod]

Ok, cheers.

It looks like the diesels are different to the petrols given we've both got 2004 Jap models?

I've taken the plunge and ordered an ELM327 based PC interface and will see if that works. Once again it's supposedly compatible with all current standards. (For AUS$32 I figure I'll give it a try! )

[hamsta]

2.5 V6 auto. 25K average 21-23 mpg.(US Equivs) Always run K&N factory A/filter. 10W-40 Semi-synthetic. Have varied speeds from 50-60mph and no gains to speak of. I think they are limited by the brick-shape as much as anything. Also quite heavy (solid). Run std HT tyres at 30psi. Was told don't go higher or will wear out centers too quickly. Use our 91 fuel and keep everything up to scratch.

[nprecon]

I scanned the five pages of threads on this subject and didn't hear much (antything?) mentioned about exhaust mods. A Cat back system using larger diameter tubing (1 7/8" stock tubing for example, replaced with 2 1/4" ID tubing) PLUS adding a quality turbo muffler, coupled with a K&N air filter cartridge SHOULD bump up your MPGs. Even if you are driving high altitudes regularly with the steep grades, you SHOULD see an improvement. Will you go from 21 to 25MPG? Don't know, but if your driving habits don't change you SHOULD see an improvement of at least 1 - 2 MPGs.

I agree with several forum comments about the truck not beinig built for economy. A GV has the aerodynamics of a concrete block being pushed down the road.... however, ALL engines are nothing more than air pumps. Increase the air you can pump into the engine complemented with more air you can push out, makes a more efficient engine. Another side is you will notice a little more OOMPH!!! in the way it runs... which you need to be careful of not using a heavier foot and loosing the econmy mods you gained.

[Sasquatch]

An update on our switch to the Esteem (1.8 auto trans).

The wife likes it. Not as much as the Grand Vitara, but she does like it. I have been sorting through the typical used car issues getting it up to my standards. The last person to change the oil in it put 15/40 dino oil it, so I changed it back to 10/30 synthetic.

Our first tank of fuel netted us 27mpg, and that has climbed to 30mpg on our last tank. This is 40/60 split of highway/city driving. I expect at least 2 more mpg with the lighter synthetic oil and the cruise control I am in the process of installing.

At the current price of fuel, it is saving us about $90 a month on gas. We were able to pay cash for the rig with the money we got from the Vitara.

It feels quicker than our GV. Even with a smaller motor, it scoots really well when you hammer the throttle. It is not as large inside, so I am a bit more cramped, but I do not drive it very often. If we are going out for dinner, or run errands together, we take the MB SUV.

All in all we are pretty happy with the switch and the savings in fuel.

[Max]

So far, so good. Cool!