few q's, hubs, td42 performace/economy.

[Geoffy91]

how ya goin fellas,

im using my phone and find it hard to search plus i havnt found much regarding this,

i have a 91gq lwb td42

first up and most important, locking front hubs, but keeping in 2wd mode unless i get stuck. Big no no? Or perfectly fine, only on dirt,gravel and mud, i never do this on road

secondly, people are saying they get 600kms out of there 80litre tank, i struggle for 500km, freeway and town, i have 33s though, so i be concered? Both Air filters are clean, serviced reguarly, puff of white smoke whenever shes dead cold, slight black exhaust puff when giving the berries in a bog ive been told,

thirdly, i cut out centre muffler and angled down and to the side just before the back wheel for some noise, feels like shes faster, revs easier and sounds like a truck, does she need backpressure? Just a note the exhaust still sits inside the chassis so i wont smash or get the exhaust hung up while 4wdriving,

any answers would be appreciated, im slightly concerned with economy and white startup puff.

[Mazodude]

well the first one I can answer.
general rule of thumb is once you leave the black top, lock the hubs :D

[YNOT]

It is OK to drive around in 2WD with the hubs locked, you can even do it on sealed roads as long as the transfer case stays in 2WD. Once the hubs are locked you can shift between H2 and H4 on the move.

Your fuel economy is a bit on the high side but nothing dramatic, how many Km's has the car done? Your injectors and injector pump may be a bit worn, your engine may be worn as well depending on mileage. There are many other factors that could contribute to high fuel consumption.

Engines don't need exhaust back pressure, they need velocity. There is a thread on here somewhere that explains this very well.

Tony

[Geoffy91]

Thanks guys taken the edge off me, its a tough as nails silver top engine as well and shes only pushin 265,000kms. so i dont understand. thats with a little bit of 4wdrivin involved, when i go full 4wdrivin i get around 350-400 outa my tank. thirsty but not as bad as it could be

[Mazodude]

might I also suggest a long range fuel tank.

[Johny]

Thanks guys taken the edge off me, its a tough as nails silver top engine as well and shes only pushin 265,000kms. so i dont understand. thats with a little bit of 4wdrivin involved, when i go full 4wdrivin i get around 350-400 outa my tank. thirsty but not as bad as it could be

I just bought one of these... i was hoping for better milage than that..
Still to pick mine up and test

[bushbikie]

I usually get around 600km's before needing to fill the tank (have gone to about 690km but then had to call RACQ - bugger!) - that's all blacktop and 95% highway driving on a 93 Mav LWB TD42 with 530000Km's on the clock. Offroad also drops to around 350-400 depending on terrain.

[GreaseMonkee]

Geez I must be lucky.....running rural k's but hilly/mountainous, driving easy, and I'm getting 11ltrs to the 100klms in my 88 Mav LWB TD42, stock truck as well with 400k on the clock, but up to around 13ltrs if I give it a bit up the mountain though!

[Geoffy91]

wow, can i ask what you guys rev the engines to before you shift?

[bushbikie]

I'm not usually light on the throttle - gear shift is at about 25-2700 but the old girl's gross weight is about 2.7t - (I'll say it before anybody else does - "......and the truck's even heavier :) " - got the drawers chockers full of crap and have a 3/4 length ARB roof rack which really should come off but the damn thing's handy when you need it. So all in all I'm happy with it's performance, just wish work would pay for the fuel instead of me........

[sleeping giant]

i have a 90 model diesel mav with a dts turbo 3" exhaust about 10psi boost. only get 600km's max if i push it

[canuck]

I've NA TD4.2s. The auto gets about the economy you were getting - somewhere between 12 - 15 L/ 100 kms. The 5 spd's best was 9.8L/100kms - right after an IP rebuild and new injectors.

For the exhaust, most gov regs require that it exit the vehicle out the rear or out the side behind the passenger compartment.