Is my Fuel Economy ok?

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

3.4 V6 5vzfe Auto. 225/75R16 tyres @ 30psi.
I have looked back over a couple of past threads and it seems like my Prado is a little on the thirsty side.
Full 70L tank only got 350 kms around town (20L/100KM) Pretty much all short 10km trips to and from work and to the shops etc.
Refilled 70L tank and did a trip up the coast and back and then a week of short trips to and from work. Got 500kms to that tank so roughly 14L/100KM.

The reason I am concerned is that I used to own a 4runner with the 3.0L V6 3vze engine and I was told that the 5vzfe was not only more powerful but more efficient than the 3vze. I know the Prado is bigger but it also has much smaller tyres than what my 4runner had.

Could it be that the auto is much thirstier than the manual transmission? Or do I have a potential issue here?

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

That seems pretty spot on mate. How many kms have you got? Timing belt due? plugs? Fuel filter? Air filter? Transmission serviced?

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

374k kms, not sure on the history it was a friends wifes business car so had regular servicing up until a few years ago. Will change plugs, air filter and tranny fluid in the next few weeks but they look ok. Is the fuel filter hard to change?

[K & M McF Senior Member Find all posts View Profile Close K & M McF]

Around town (I am assuming you drive to work in a city), I would say a lot thirstier than it should be. When I used to use mine to travel to work and in heavy traffic, it was always about 14.5 l/100 km. However, how do you drive? I see people who drive large cars/4WDs who zoom off from traffic lights, accelerate like they are in a race. I often wonder what their fuel economy is like. Try a week of driving very conservatively, accelerate slowly (well not so slow you annoy people), look ahead and ease off when you see traffic stopped. See if economy improves.

For the second tank, sounds reasonable considering country trip and then work travel.

Also, you have very low pressure in your tyres. Most people run 35-40 psi front and 40 psi rear.

I now mostly only use my Prado 90 to tow my 2+ tonne boat within Sydney. My economy is under 20 l/100 km when I do this.

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

Nope. Fuel is fairly easy to get to. it's essentially under the front passengers butt! Crawl underneath and you'll find a skid pan on the passenger side and it's mounted to the chassis rail above it. From memory, the filter has a 14mm nut on it and the pipe is a 12 mm. If it hasn't been done in a while then I strongly suggest the use of flare nut spanners. Last thing you want is your open ended spanner slipping and kinking the fuel line. Truck won't go anywhere when that happens.

There is a few things to know about servicing the trans before tackling that one. First off... most resources will tell you that you need 2 litres to do a drain and fill...most people find they need about 7 litres instead.

When you first go underneath you'll see the exhaust y pipe cuts across the front of the pan. Any thoughts of being able to do this job and working around the exhaust can be thrown out the window. The y pipe just HAS to be removed. While you're at it, loosen the sway to body mounts also. As you do this, you will probably notice the sway bat to body bushes are flogged to hell. So spend the 50 bucks and have a new pair ready to go in. Very simple to replace Added perhaps 5 minutes to the job and it feels like a whole new machine afterwards.

Now in regards to the filter and gasket... there seems to be two schools of thought on this. First is that since the filter is only a wire mesh, there is no sense in replacing when you can simly pop it out, clean it and shove it back in. Then you can use gasket goo to seal the pan back on and it won't leak. Very valid method... biggest downside is when you pull the filter it has a cork gasket around its nozzle and if it's seen better days than you need to replace after all.

Second school of thought is that you should replace the filter and don't use gasket goo but use the cork pan gasket that comes with filter. This method requires a little more due diligence in making sure that the old gasket or silicone is completely removed otherwise it will leak with the gasket.

While neither party would argue I'm sure that always replacing the filter is the better option, as a member of the second school myself I will say that it's often redundant and a waste of money. If on the other hand you don't know when it was last serviced (going in for a regular service usually means nothing more than checking the trans dips tick if that) then I highly recommend replacing that filter.

The cork gaskets are definetly prone to leaking when it comes to alloy trans and steel pans. But there is a trick that I do personally that has meant I've never had a leak. Two to three days after servicing, I roll back under and snug up the pan bolts again.

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

Valid point on tyres. I run my 265 70 16s at 38.

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

The tyers could be part of the issue of economy. Got back from Inskip over xmas holidays and wasn't sure what to inflate backup to. Ill put a bit more in and see if that helps. I drive like a grandma, average 2000 rpm and only ever get it up over 2500 rpm if I am going up a hill or need to overtake someone who is slower than me. I don't think I could be more fuel efficient if I tried lol.

Thanks for the tips RanJ. Fuel filter sounds like the same as in the 4runners and the tranny seems like there might be more to it so ill research it and go back over your post when I get time to look at it.

One final question, the Prado's engine seems to be quite noisy. Sounds like the radiator fan is running all the time. My old 4Runner used to sound like this when I first turned it on but once it had warmed up a bit it turned off until the temperature ever rose or I stopped at a set of traffic lights and it needed to come on to help cool the radiator. Prado sounds like the radiator fan is running 24/7 no matter how warm or long the engine has been running. Is this normal?

[rickyboy Lurker Find all posts View Profile Close rickyboy]

Hi fishtank if your fan is going all the time then I believe the fan clutch is at fault and would explain your high fuel consumption. Check your fan clutch with engine off first by simply spinning the fan by hand, if you cant then the clutch is seized if it spins freely then start engine from cold and let idle for 30 seconds or so if it keeps pumping out a lot of air then its not seized but is faulty and needs to be replaced. Hope this helps.

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

It spins freely when engine off. Started it up and waited a minute and its still spinning but it is a hot day and engine wasn't cold cold so I will try again in the morning. If it keeps spinning the fan after the 30 seconds from cold what needs to be replaced? Is it costly and/or expensive and is it something I might be able to do myself?

[Walky88 Member Find all posts View Profile Close Walky88]

It spins freely when engine off. Started it up and waited a minute and its still spinning but it is a hot day and engine wasn't cold cold so I will try again in the morning. If it keeps spinning the fan after the 30 seconds from cold what needs to be replaced? Is it costly and/or expensive and is it something I might be able to do myself?

Not very expensive. My local repco has a dayco fan in stock for a retail price of $224.

As far as changing undo 4 12 mm nuts holding viscous fan on, loosen belts and then replace.

[AfricanPrado Lurker Find all posts View Profile Close AfricanPrado]

2000, 3.4l V6 petrol Prado, 140,000 kms, almost totally city driving: average fuel consumption over two years of 14.6l/100km (I believe this is 16.1 mpg). Tyre pressure kept at 2 Bar (29 PSI) as recommended on plaque in driver's door. Does this sound wrong? Tyre pressures quoted by others seem a little high to me. I am no grand prix driver and here in Burundi there is VERY little chance to go really fast. I assumed fuel economy, or lack thereof, was a feature of the truck with which I simply had to live. Shall read any advice with great interest!

[oceanracer Moderated member Find all posts View Profile Close oceanracer]

How many ks to both tanks are you getting,, , thanks

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

I nearly always pay attention to the sticker inside the door of every car i own except for the Prado. I chew through tyres so quickly at 29psi... well, I chew through the outer edges and have a tonne of tread in the middle.

[Walky88 Member Find all posts View Profile Close Walky88]

I run my tyres (265/70 R16) at 40 psi.

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

Yeah seems to be a pretty consistent thing for us 90 95 owners to ignore that and run at least high 30s.