strange highway fuel economy

[zskinner]

so i used to have some transmission issues and the torque converter would never lock up at 88 km/h like its supposed to, therefore cruising at 100 k's on the highway the car would be revving at around 2100 revs or so. i used to get 8L/100km fuel economy when it was doing this. i have since fixed my transmission problems and it goes into torque converter lockup with no trouble everytime now, so now the car revs at 1800 revs which is alot better, but im now getting 10L/100km highway fuel economy (so the fuel economy has gotten worse now that torque converter lockup works). does anyone have any ideas on what the hell is going on lol. ive changed the oil and filter, spark plugs and leads, o2 sensor and i also installed a transmission oil cooler but that hasnt helped highway fuel economy at all (it helped city driving but not highway cruising). anyone have any ideas? any input would be great

[zskinner]

no ideas at all? im open to any suggestions, this is really annoying me as im starting to do more and more highway driving the past few weeks so improved economy would be very nice indeed lol

[delcowizzid]

its cause of the extra load on the engine with it locked will reduce timing and pump in more fuel i never even select 4th till 100kmh+ if i drop under 100 its straight back to 3rd to bring it back to 100 saves heaps of gas

[nstone63]

staying with the transmission/fuel economy thing, what's the difference between 'blue D' and 'normal D'?

What do the two gears actually change about the way the car runs in the city?

[delcowizzid]

its a different gear ratio in the 2nd D its overdrive.people who drive round in 50 zones in 4th as soon as you touch the gas pedal to accelerate the load goes pretty high and drops timing and adds fuel if you do the same in 3rd the load variation is a lot smaller so timing stays higher and fuel stays less as well great for economy round town

[padrickz88]

White D is 3rd gear, the blue is 4th.......

On a car with stock gears, i wouldn't even bother using 4th till after 80k's...

[somefool]

ooh, so basically in white 'D', up to 90kph, even though the engine would rev up higher, it would use less fuel than driving around in blue 'D'? Im all about economy because money is tight, i drive like a grandma in blue 'D' and get 550ks out of a 63L tanks tops

[zskinner]

its cause of the extra load on the engine with it locked will reduce timing and pump in more fuel i never even select 4th till 100kmh+ if i drop under 100 its straight back to 3rd to bring it back to 100 saves heaps of gas

ahhh true thanks mate, any chance do you know if theres a way to disable the lockup altogether, or better yet is there maybe a way to hook up a switch to engage and disable it or something?

[delcowizzid]

you dont want to disable it or youll cook the trans

[delcowizzid]

is it running a vp tune running the wrong tune will make it labour along and suck fuel doesnt have a vn tune in it by accident

[zskinner]

oh ok makes sense it would cook it actually ay. nah mate ive got a greenfoam tune meant for a vp, so shouldnt be that. looks like ill just have to hack my shit fuel economy for a while till i get a new car lol..... thanks for all your help mate

[joe seinfeld]

oh ok makes sense it would cook it actually ay. nah mate ive got a greenfoam tune meant for a vp, so shouldnt be that. looks like ill just have to hack my shit fuel economy for a while till i get a new car lol..... thanks for all your help mate

so ive got a vn with a VP motor in it, and i gt shockin fuel economy im talkin about 200k's to a tank.

Ive noticed that vp's dont have another blue D but a 3rd, does this make any difference.

i used to drive with it in blue D, then i noticed when i shifted it into normal D it would sit at less revs from about 60km/h onward

i know thats a bit wordy but basically what im asking is since ive got a VP motor in a VN, should i be driving in normal D all the time? thats how it feels

[zskinner]

mate if your only getting 200k's then something else is up. the normal stuff to look at is your oxygen sensor, spark plugs and leads, tyre pressure, cleaning out your air intake, and just a general service. good luck with it

[nstone63]

So the bottom D is the better option for around town, and save the top D for the highway/ faster roads?

[vps231]

Burnouts!!