Fuel Consumption V6 Engine

[Jezz Lurker Find all posts View Profile Close Jezz]

I've been reading through this thread and others on fuel consumption trying to find answers to my own higher then usual fuel consumption problems. I'm cleaning the MAF sensor today to see if that helps.

What's caught my interest is the discussion around octane ratings and how the engine management system adjusts the ignition.
For reference on how this operates see http://www.lcool.org/technical/prado...tane_fuel.html

I'm running my 120 Prado on LPG. Now LPG has an Octane rating of around 108-110. If you use a high octane fuel the engine management system will advance the ignition to suit over 3000-5000km, at which point you should be getting more torque and improved fuel consumption. It sounds like if you then run a tank of 91 Octane fuel through, the knock sensors will trigger the engine management system to retard the ignition to suit, and it will take another 3000-5000 km to advance the ignition again if you go back to 98 Octane fuel.

My Prado starts on petrol and switches to LPG after about 1km. I do most of my Ks on LPG. I fill my petrol tank with standard 91 Octane unleaded. This has got me thinking I'm doing myself a disservice. Maybe I should always fill the petrol with 98 octane as this will help the engine management system to advance the ignition to better suit the high octane petrol and LPG. The ignition would at least be advanced to suit the 98 octane petrol, which should also be an improvement for the LPG hopefully giving me more Ks out of each tank of gas.

Does anyone more knowledgable on this have a considered view?

I'm going to switch to Premium unleaded to test this out and see if my LPG consumption improves.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Sounds logical and sense there Jezz. Post up when you have tried it out and giveus your results..Cheers Steve

[Shimple Lurker Find all posts View Profile Close Shimple]

Let me start by saying g'day, first post and all.

For ages I have complained about my 2005 120 v6 in relation to its fuel economy. I have added a scan gauge and have also run it on premium for over 5000kms, with no change. Both tanks full around city would give me just under 1000Km's. Towing bike trailer would see me dropping about 100Km's, downtown 900Km's off both tanks.

About 4 weeks ago, I hit 90,000 on the clock. Suddenly I am getting 1150Km's to both tanks(not towing). Can't for the life of me explain why?

Has anyone experienced something similar?

Btw, I love the power of the petrol, and wouldn't change it for the world.

[timmay5.7 Advanced Member Find all posts View Profile Close timmay5.7]

Did you get it services at 90,000? That might help...
Or it's just run in.

[Shimple Lurker Find all posts View Profile Close Shimple]

Have not had the service as yet. I did however go to a brand new servo, with brand new tanks. That shouldn't explain the difference though should it. If so, have i uncovered a can of worms regarding old servo tanks and the quality of fuels?

I run 98 Octane.

[double_d69 Member Find all posts View Profile Close double_d69]

19.5 now running on 33" tyres... owch! have been giving it some right boot though

[fortom Lurker Find all posts View Profile Close fortom]

Easter weekend trip to Hervey bay and Bundaberg from Brisbane - 91 octane fuel 4 adults and a small amount of luggage. Normal road
legal speed limit a/c on - 12.60l per 100k. Very happy with that figure.

Now if we can fix the dash..........

Tom

[Amit Lurker Find all posts View Profile Close Amit]

Just got my SVI LPG kit installed, 310 Kms Sydney city driving out of 62L LPG from first fill, MAF sensor cleaned today, hoping for better economy

[kav Avid PP Poster! Find all posts View Profile Close kav]

i haven't looked at this post for a long time , but i just did a trip , syd - yass , yass -syd ,towing a car trailer with car both ways at 2300kgs . the fuel computer recorded 17.5/100km for the whole trip . not too bad considering my mates girlfriend tows a boat at the same weight with a 120 diesel for 14.5/100km . hmmmm figure the cost of diesel v petrol ?

[rusty_burrows Lurker Find all posts View Profile Close rusty_burrows]

hi guys with my petrol prad 4.0 v6 uses more petrol then i can put in it.. im running 4.88 diff ratios with brand new 33" tyres i have changed every filter and seriviced everything the only thing i can think about doing is supercharging it to make it run a little leaner i know my fuel cost would still be high but at least i would have ample power to play with off road. what do you guys think

[Hutch Addicted PP Member Find all posts View Profile Close Hutch]

Let me start by saying g'day, first post and all.

For ages I have complained about my 2005 120 v6 in relation to its fuel economy. I have added a scan gauge and have also run it on premium for over 5000kms, with no change. Both tanks full around city would give me just under 1000Km's. Towing bike trailer would see me dropping about 100Km's, downtown 900Km's off both tanks.

About 4 weeks ago, I hit 90,000 on the clock. Suddenly I am getting 1150Km's to both tanks(not towing). Can't for the life of me explain why?

Has anyone experienced something similar?

Btw, I love the power of the petrol, and wouldn't change it for the world.

Yes I had the same thing after the 100k service I seemed to pickup a hundred l a tank, also about the same time I added the scan gauge, Did it just make me drive more conservative?? But certainly when I sold it I was getting the best economy of it's life.

[Richoson Avid PP Poster! Find all posts View Profile Close Richoson]

Yes I had the same thing after the 100k service I seemed to pickup a hundred l a tank, also about the same time I added the scan gauge, Did it just make me drive more conservative?? But certainly when I sold it I was getting the best economy of it's life.

Hutch

You drive conserative c'mon!! You drive it like you stole it

Richo.

[grande1810 Junior Member Find all posts View Profile Close grande1810]

Just towed 24foot van from Gladstone to Mackay used about 20 more litres of 98 octane with van than without, gotta love the V6 power and being able to tow at a constant 95 to 100 kph.

[Jurgs Junior Member Find all posts View Profile Close Jurgs]

For anybody that is interested in consumption figures with lpg conversion (Sprint Gas System). Just had the conversion done two weeks ago and have used 17l/100km for both of the first two tanks. Filled up for 55c/litre both times so very happy with these figures. Conversion should pay for itself within about 1.5 years. Will try to see if the theory of running 98RON in the petrol tank for the next 3000-5000km will retune the motor to run even more efficient now.

[phillo Lurker Find all posts View Profile Close phillo]

managed to achieve 12.6 with my petrol engine, on long trips. regulary acheives around mid 13's though.

Has anyone heard of a chip which is placed in the petrol engine computer to improve its economy? apparantly this has been done to mine, dont really know how to tell or not though