We have remapped the car and feel 6th could be a little taller to improve economy. Aas 6th is mainly used on motorway I feel car could handle with running at 1800 rpm at 70 maybe 2000 rather than over 2500 given the extra torque thanks to shark.

Do had anyone tried this successfully

taller gearing!! it will do over 170mph GPS as has been proven by a fair amount of people, how much taller do you want the gearing to be!!

We have remapped the car and feel 6th could be a little taller to improve economy. Aas 6th is mainly used on motorway I feel car could handle with running at 1800 rpm at 70 maybe 2000 rather than over 2500 given the extra torque thanks to shark.

Do had anyone tried this successfully

I'd not bother, baswd on my experience with my own remapped vRS TFSi & my partner's VW EOS.

They both use the BWA engine & have had stage 1 remaps from AMD, but the VW does have an overall higher final drive ratio & it shows!

Cruising on the Autobahns the EOS is a little more relaxed at 100 mph+, but it looses the flexibility that I enjoy in the Octy.

I find that in the EOS I'm changing up later & that I have to remember that I've lost the extra "kick" at lowish engine rpm's that the Octy gives.

As for reserving 6th for motorway work, no way! My car is quite happy keeping up with the traffic flow from 1500 rpm upwards, which is about 38 mph in 6th.

(It's possible, but pointless to start in 1st, spin up to 6K rpm & then shift straight into 6th......, more importantly block shifting in town traffic is normal

for me, made possible by the superb flexibility of the TFSi lump!)

DC

As for reserving 6th for motorway work, no way! My car is quite happy keeping up with the traffic flow from 1500 rpm upwards, which is about 38 mph in 6th.

Not good. This is DMF destroying driving.

None of which helps my post only interested in dropping revs on the motorway.

Not interested in breaking speed limits looking for lower revs at legal motorway speed.

Happy with flexibility in first 5 gears but want to make cruise at 70 more economical in 6th which is why I asked not to increase top speed which I will never even try to see

Yes its remapped it increases flexibility and the torque was more important than the bhp for me.

I prefer petrol and do take car to red line when mood takes me. But if I could get a few more mpg at 70 by running at 1900 rpm rather than just over 2500 I would consider it

Perhaps you could find another internal gear-set with a higher 6th gear?

The costs of making any changes to the transmission might take some time to reach the break-even point.....

As for comments re. clutch, flywheel, tyres & DPF, I run a petrol vRS...., that's quite happy to plod around town

without feeling uncomfortable at lowish engine RPM'S.

I've driven enough miles, & in a variety of vehicles to aquire a modicum of mechanical sympathy!

(EG, don't try to stick to town speed limits in a 105e Ford Anglia in 4th (top) gear, it won't work....)

DC

Not good. This is DMF destroying driving.

Maybe but keeping above 1500 rpm means driving round town in 3rd!

Another option is a diesel gearbox but I expect you would need to be whacking on to even get into 6th.

IMO the ratios are fine from the factory whatever tune you have and I very much doubt you'd see much improvement over stock box, you're only at stage 1 let's face it.

Well 60mph sees 40mpg.

If the final drive was higher so running same rpm at 70 or date I sat it indicated 75 it would be great to get that mpg at the higher speed

Planning on keeping the car a long time do as long add break even is within 3 years worth out for us.

Plus might be increasing annual mileage

Maybe a diesel vrs would be a better idea for you if your wanting very good mpg at motorway speeds & your annual mileage is going to be increasing?

Had a diesel in the pay and do not like them really.

Plus cost to change will nor make it cost effective.

Was hoping for a simple not too expensive solution..

Maybe I wool just crawl on the motorway instead

Edited 16 January, 201313 yr by solwood

Lower revs does not neccesarily mean better mpg, you need x amount of energy to push a car at any given speed, also the engine will have a sweet spot where it is most efficent so you need to research more before doing it, whoever mapped the car could probably give advice on that

Have you thought of LPG, tried & tested

Alternative is bigger diameter wheels ------------------------ YES IM JOKING

Edited 17 January, 201313 yr by Stuart_J

Lpg would be interesting but not seen anyone fitting it to a tfsi. Mind you the higher octane would be fun.

Mac torque from 1800 so that should be a sweet rev I would have thought

Might be too long for return in investment

Umm... The formula for calculating the force to move the car has a squared term for speed. Thus 60^2 = 3,600 at 70 is 70^2 = 4,900, this gives a factor of 1.36. This means it takes 36% more energy to travel at 70 over 60. This means that its more do with physics than gearing....

Lowering the car might be a cheaper to increase mpg. Slight gain, but will reduce frontal area, its what all the manufactures do on there eco models...

As for reserving 6th for motorway work, no way! My car is quite happy keeping up with the traffic flow from 1500 rpm upwards, which is about 38 mph in 6th.

Not good. This is DMF destroying driving.

(Sorry for the double-quote.) Does the petrol VRs have a DMF? Old newbie2's profile says he has a petrol.

I often drive in this way as I've found it to be most economical if that speed can be maintained (ie just needing to feather the accelerator to keep it going, fairly level gradient). 5th is good from 30. Put it in a lower gear and it seems to be necessary to push the accelerator further down to keep the same speed, and the MPG goes down as a result. Is this a problem even if I don't try to boot it from 1500-ish (which I wouldn't, I'd change down)?

@thewez - speed does have something to do with it (to overcome increased friction etc), but so does gearing. Otherwise it would be as economical to drive in 3rd as in 6th at 70mph.

Thanks for noticing that I drive a TFSi vRS, & that they don't really have a requirement fo a Diesel Particulate Filter................

Also, since the petrol vRS is lower geared than the diesl verions, the internal ratios on a petrol feel as if they are closer.

Given that the TFSi engine has a much wider rev range than a diesel, pulling from approx 120 rpms to the 6500 rpms red-line, & is blessed with a really flat torque-curve, then it's able to exploit said characteristics to provide one with the ability to plod around town roads & country lanes (in the snow soon, perhaps?) or to drive like a total lunatic should the red mist descend....

As for better economy at motoway speeds, we averaged app 38 mpg in Europe last year, which is economical enough for this OAP!

Fuel economy is not a big thing for me, in the last 20 months I've driven 5k miles in the Ford & 13K in the Octy, much of that discretional driving,

so I don't have the worries that a others have regarding commuting & necessary mileage.

One of the joys of retirement, I guess.

I'm thinking of getting rid of the vRS this year, maybe for an Octy 3, or a Golf 7 & I'd not consider a diesel in a these cars at all, my annual fuel savings wouldn't compensate from the pleasure I get from modern petrol engines.

(I can't take money to the grave, I might as well enjoy it now, IMVHO.)

Cheers all, DC.

Thanks for noticing that I drive a TFSi vRS, & that they don't really have a requirement fo a Diesel Particulate Filter................

"DMF" (dual mass flywheel), not "DPF" - we may not be off the hook yet! But elsewhere on the forums, both seem to apply to the diesel only.

Sorry to be the bearer of bad news a also have a DMF.

For that reason I prefer to keep revs over 1500.

Pootling in town at 30 in 4th, but not comfortable in 6th until doing 50, oh and 40 for 5th.

Lower revs must save economy otherwise why have companies created 6,7,8 speed boxes to enable us to drive more economically. Third is good for more than the legal limit but drive at 70 in third and I guarantee I will use more fuel