Optimum speed for mpg

What do you guys find the optimum cruising speed for good mpg? im talking about motorway speeds?? Esp. those with TT autos like mine.

I've yet to find it mate.

cruising between 3K and 3.5K should not be far from the mark, but don't expect way over 23-25mpg.

I haven't seen better, and I'm still trying. Got a new oxygen sensor to fit, although the old one seems to be accurate enough (judging by the wideband figures)

Even with optimal tyre pressures etc, I've yet to better 25mpg under normal(ish) motorway driving (80-100 mostly) with a passenger.

Spirited driving is 18mpg mixed.

Others have seen 30mpg at times, at around 80mph, so it shouldn't be impossible.

I've yet to find it mate.

cruising between 3K and 3.5K should not be far from the mark, but don't expect way over 23-25mpg.

I haven't seen better, and I'm still trying. Got a new oxygen sensor to fit, although the old one seems to be accurate enough (judging by the wideband figures)

Even with optimal tyre pressures etc, I've yet to better 25mpg under normal(ish) motorway driving (80-100 mostly) with a passenger.

Spirited driving is 18mpg mixed.

 

Others have seen 30mpg at times, at around 80mph, so it shouldn't be impossible.

Thanks John. i ask because strangely enough i find i am getting better fuel consumption travelling at around 75-80 mph then at 65-70mph...strange.

Yes, I've seen that too.

Looks like with the auto's gearing the engine operates in a more efficient rev range at around 80mph...

Yes, I've seen that too.

Looks like with the auto's gearing the engine operates in a more efficient rev range at around 80mph...

Excellent. What would you say would be optimum pressures for 1 passenger, full tank of go juice on standard 16's??

I was going to say the question should have been 'optimum RPM for MPG', but then you don't have much control over RPM in an auto ;-) only joking

I find in my TT6-speed that cruising at 2.5K rpm in 6th is the most efficient. I can get upto 30-32 mpg on a motorway. That equates to something like 70mph.

are your cats in right now Aaron? i'm doin a long trip tomorrow, might try it then and compare but mine are out at the mo

When i bought my TT, the engine management light came on if held above

3,000 rpm for more than 8secs ! !

As it turned out it was the gearbox Speed Sensor and wouldn't have caused any MAJOR AGG

but, because of that i had to go all the way to Cornwall - bop around a bit (locally) and all way back keeping it under 3,000 all the time.

It returned 31mpg AVERAGE after i filled up at end of TO trip.

It returned 30mpg AVERAGE after poodle AND return trip.

ALMOST impossible to repeat once you have full use of second turbo, but,

proves you COULD achieve 30/32 IF you had need (?) to.

[ps. that was the LAST time i ever got THOSE figures.... best on a run

AFTER that was ~27....town after that always averaged ~16/18]

FatS.

both CATs are out on my beast

SORRY....

Jap TT,

NO mods,

Mongoose WITH cats (so basically Standard zorst)

AUTO.

..but then you don't have much control over RPM in an auto ;-) .

You haven't got full control, true.

But with the supra's box you can have some control while being in 'overdrive off' mode (forcing the revs to be higher at non-motorway speeds)

You can also have lots of control in 'manual' mode, but you're not gonna be using that when going for optimum mpg

I find in my TT6-speed that cruising at 2.5K rpm in 6th is the most efficient. I can get upto 30-32 mpg on a motorway. .

Other things being equal, the auto will always return worse mpg figures, there are more losses in there by design.

hmm... next supra i'm going to have will deffo be a manual then

27mpg at a steady 80 cruise, not much better at a steady 50mph (don't ask why, it wasn't my fault ). Not bad all mods considered

-Ian

I too have found 70-80 is just as if not more economical than 50-60.

Thread here for ref: http://www.mkivsupra.net/vbb/showthread.php?t=24970

And it's not the EGR working either, because I've got it disconnected and the mpg follows the exact same pattern