What is 6th gear for?

[jettapilot]

I rarely drive faster than 120kph. On my recent country trip I noticed that whenever I slipped into 6th at, say 110kph, revs drop to ~1800 and fuel economy decreased. I feel most comfortable driving at ~2000rpm which means 3rd gear around town at 60kph, 4th up to 90kph an 5th on the freeway/open road up to 120kph.

6th must be for 140kph on the autobahn.

What are your thoughts/experience?

[h100vw]

Without a doubt 6th is for saving fuel. The circumstances have to be right though and it is possible that using 5th would be better for economy.

Consider that in the home of VW the autobahn is unrestricted in places. Not a bad thing IMO

Gavin

[Jimanjen]

This is an interesting question....we drive a five day a week 45 klick each way commute to work,it is on a winding,country road,between two towns...we have no traffic lights,the occassional truck,and generally have a very nice drive to and from work.We often exceed 120 kph,coz its safe and fun,and we use sixth a fair bit.....we are more of the opinion that we dont need fifth gear!.....If we wanna pass,straight from sixth to fourth,give it heaps,a quick visit to fifth if needed ,but usually straight back to sixth. Jennie and I are still getting used to the characteristics of a diesel engine,and a manual box(we have been lazy auto drivers for many years)but it is a fun learning curve!

[Vicbitter]

I rarely drive faster than 120kph. On my recent country trip I noticed that whenever I slipped into 6th at, say 110kph, revs drop to ~1800 and fuel economy decreased. I feel most comfortable driving at ~2000rpm which means 3rd gear around town at 60kph, 4th up to 90kph an 5th on the freeway/open road up to 120kph.

6th must be for 140kph on the autobahn.

What are your thoughts/experience?

At 110kph in 6th, i'm at about 2200-2400rpm's.
at 100pkh in 6th, i'm at about 2100rpm's.
I too feel most comfortable at 2000+ rpms in any gear.
I shift at 2500 when warming up, and at 3000 when warmed. (and 3000+ when i wanna clean out the exhaust on the ppl sticking up my arse in the left lane)

[chisler]

in terms of fuel economy, I've found 6th is best when using cruise control on a "very" flat road. but if I even do some mild acceleration, or even drive up a slight inline in the road, then the economy gets blown out, and its better to drop a gear.


We often exceed 120 kph,coz its safe and fun,and we use sixth a fair bit.....we are more of the opinion that we dont need fifth gear!.....If we wanna pass,straight from sixth to fourth,give it heaps,a quick visit to fifth if needed ,but usually straight back to sixth.
I'm planing on testing out using 6th and 4th for my daily commute next week, which is a country road, and far from flat.

I'm trying to find the best performance/economy, so far only tested using 6th/5th, and 5th/4th and 5th.

[shogun2]

This is an interesting question. I use 6th driving around town at anything above 70Kph. The diesel torque is sufficient to get me going even when around the 1200 rpm.

[jets]

On a level road, the min. speeds I use are 70Kph for 5th & 90Kph for 6th. If there is the slightest incline I change down, particularly for these 2 highest gears.

[Russ59]

When ever I'm cruising along the highway, freeway, whatever way :biggrin: I hardly ever drop back from 6th gear, as others have said, with the torque of the diesels you rarely need to, especially on hills :bowdown:

The answer to the original post (why is there a 6th gear ?) would IMO have to be mainly for economy :)


Russ

[jets]

The answer to the original post (why is there a 6th gear ?) would IMO have to be mainly for economy :)
Russ

It's also to reduce engine noise while cruising & engine wear by turning at slower revs. I wish my T4 Syncro had a 6th gear. While having a low first gear & evenly spaced ratios, it revs a little to high for my liking while cruising[around 2,700 rpm & 110Kph] & probably uses more fuel.

[CatonaPC©]

Just for the record, the DSG shifts to 6th gear at around 80km/h depending on the circumstances. At 115km/h (indicated), my Golf TDI was turning over at 2100RPM or so. The torque is so good, it didn't even shift down when overtaking.

[Russ59]

It's also to reduce engine noise while cruising & engine wear by turning at slower revs. I wish my T4 Syncro had a 6th gear. While having a low first gear & evenly spaced ratios, it revs a little to high for my liking while cruising[around 2,700 rpm & 110Kph] & probably uses more fuel.

I can't honestly say that I notice a great deal of difference in the diesel as far as the noise level is concerned, not at 100 kmh anyway. Some cars really could do with the 6th gear as you say, my Father in Law has an '84 Hilux 2.2 L diesel and a 4 speed manual gearbox, now there's noise when cruising :eek: :duh: I think from memory it does about 3800 rpm @ 100 kmh, it had an engine rebuild at 300,000 k's and now has 400,000 + k's on it and it just keeps on going. :driver:


Russ

[gregozedobe]

Also 6th gear allows a TDI to have a "respectable" top speed on those unrestricted autobahns (its a matter of pride, you know ? ) :)

If we were legally allowed to cruise at speeds in excess of 130 kmh then 6th gear would be more useful than at our current legal maximums, where the engine is only just into its comfortable working speed range.

Even with the extra torque of my 2.5 TDI engine I often find myself changing back to 4th if I have had to back off on a hill for some reason. I prefer to keep the revs above 2,000 if I am asking an engine to do some serious work (and yes, I know TDIs will pull hard at 1,800, but I'm not convinced it is necessarily good for them - JMO ;) ).

[Russ59]

Also 6th gear allows a TDI to have a "respectable" top speed on those unrestricted autobahns (its a matter of pride, you know ? ) :)

If we were legally allowed to cruise at speeds in excess of 130 kmh then 6th gear would be more useful than at our current legal maximums, where the engine is only just into its comfortable working speed range.

Even with the extra torque of my 2.5 TDI engine I often find myself changing back to 4th if I have had to back off on a hill for some reason. I prefer to keep the revs above 2,000 if I am asking an engine to do some serious work (and yes, I know TDIs will pull hard at 1,800, but I'm not convinced it is necessarily good for them - JMO ;) ).

C'mon admit it you just enjoy giving the diesel a good fang don't you :driver: :biggrin:

Russ

[gregozedobe]

C'mon admit it you just enjoy giving the diesel a good fang don't you :driver: :biggrin:

No, NO ! I only do it to keep the turbo vanes freed up ;)

The excuse before that was "I need to drive hard to increase the pressure on the rings to run the engine in properly" (In the RS I just say I bought it to enjoy driving and leave it at that - thankfully the missus enjoys giving it the odd squirt too).

I must admit I get a quiet pleasure from the look of surprise from other drivers when they realize just how well my big white box goes in 3rd and 4th gear, on hills it is capable of surprising acceleration once it is moving.

[Russ59]

No, NO ! I only do it to keep the turbo vanes freed up ;)

The excuse before that was "I need to drive hard to increase the pressure on the rings to run the engine in properly" (In the RS I just say I bought it to enjoy driving and leave it at that - thankfully the missus enjoys giving it the odd squirt too).

I must admit I get a quiet pleasure from the look of surprise from other drivers when they realize just how well my big white box goes in 3rd and 4th gear, on hills it is capable of surprising acceleration once it is moving.

Yeah, these new diesel engines are a far cry from the old dinosaur diesel era, I have given quite a few petrol 6 and even V8 drivers a jaw drop when they have tried to keep up on the hills (without having to drop back gears and really floor it). :biggrin: The most incredible part is that the fuel consumption really doesn't vary all that much if you give it a good fanging on the hwy or even cruising around town in traffic, you don't get the large variables in fuel consumption that you do in a petrol car. I'm a very happy diesel camper and will hopefully stay that way for some time to come :)

Russ

[mikinoz]

It is there for bling factor. I have changed my gear knob on the TDI to 16 speed so I get some respect at the diesel pumps from prime movers! :)

[Russ59]

It is there for bling factor. I have changed my gear knob on the TDI to 16 speed so I get some respect at the diesel pumps from prime movers! :)

Haha LOL has it worked for you though ?

I still get funny looks from people when filling up with diesel, the first time I did a fill the guy in the servo at the counter said "you know that's diesel you've used in your car mate" I said thank Christ for that, for a minute there I thought you were going to tell me I'd used petrol :duh: :biggrin:

[jettapilot]

I love it when they try to sell you a chocolate for an extra 2c a litre discount and I say "No thanks. Don't need it. See you in 1000kms :biggrin:"

Especially when diesel's cheaper than petrol

[gregozedobe]

Especially when diesel's cheaper than petrol

Yes, I am enjoying that at the moment, but I don't expect that happy situation to last for very long. I've been running diesels for over ten years, and I think diesel has been cheaper than std unleaded for less than 10% of that time :frown:

[CatonaPC©]

It's cheaper now because the dealers need to move all those diesels in the yards. Then when they're all gone, the oil companies will jack up the price! :smile:

[Russ59]

I think unleaded has just been put up in price because of the economic downturn, with the drop in interest rates and the money people are finally saving there, the petrol companies figure it's a good time to screw everyone for an extra few dollars to fill the car instead (they've gotta keep their multi billion $ profits in check). I know someone will come back now and say it's all to do with world oil prices etc.. etc... blah ..blah ..blah, but we've heard it all before, no matter what anyone says, they have us all by the short and curlies - You can't win :frown: :brutal:

As far as diesel prices being a few cents P/L cheaper at the moment, let's enjoy it while we can, it can't last :frown:


Russ

[Greg Roles]

Asian demand has dropped, thus the famed "singapore index" on diesel has dropped. We are reaping the temporary benefits.

You can win Russ, and it's a large factor in WHY I bought a diesel.

Bio. I'll be doing it out of sheer principle once the car is paid off in a few years time. Am building my side "Bio" shed this year.....:biggrin:

[Buller_Scott]

I shift at 2500 when warming up, and at 3000 when warmed. (and 3000+ when i wanna clean out the exhaust on the ppl sticking up my arse in the left lane)

Hey, me too!!!!

[broady69]

I used to have the Polo TDI in South Africa and you can get away with 140km/h between towns and it was definately more fuel economical to travel in 6th than 5th.

I suppose it's easier for them to put in the same gearbox for all Models regardless of the country they go to.

Otherwise the Vietnam batch would probably only have 2 gears. :)

[Russ59]

Asian demand has dropped, thus the famed "singapore index" on diesel has dropped. We are reaping the temporary benefits.

You can win Russ, and it's a large factor in WHY I bought a diesel.

Bio. I'll be doing it out of sheer principle once the car is paid off in a few years time. Am building my side "Bio" shed this year.....:biggrin:

I suppose the main problem with the GT TDI and running it on BIO now is the DPF no doubt ? :duh: Mine had another cold regen this arvo but instead of the usual pull over and let it idle for a while approach, I decided to give it some stick instead. I'm going to book it in for a check up because it really runs like a dog when it does this and I just don't think it's right. The trouble is the bloody thing never shows any error codes so as far as the dealer's concerned there's nothing wrong. I give it a decent run at least once a week but it still seems to think it needs a regen. I have been running it on Mobil diesel since I got it, would there be any benefit do you think in trying another brand of fuel ? I have nearly 10,000 k up now and it's been averaging around 7L/100k on the last few tanks, which is still very good IMO for a combination of probably 70% city / 30% hwy driving. :driver: Sorry for going off topic somewhat but it's still within the realms of the original thread when we are talking economy. :)

Russ

[CatonaPC©]

I have been running it on Mobil diesel since I got it, would there be any benefit do you think in trying another brand of fuel ? . . .

I'm quite surprised you haven't done so already. Are you filling at the same service station all the time?

I'd certainly suggest trying a different brands particularly from a place were the stocks are replenished frequently. If your DPF still plays up, then you certainly have a basis from which to bring it to the attention of your service dealer.

[Russ59]

I'm quite surprised you haven't done so already. Are you filling at the same service station all the time?

I'd certainly suggest trying a different brands particularly from a place were the stocks are replenished frequently. If your DPF still plays up, then you certainly have a basis from which to bring it to the attention of your service dealer.

I have been filling at the same servo near home since new, it's a very busy one and stocks would be replenished each week I would imagine. I still think there could be an issue with the DPF but the dealer basically won't do a thing about it unless it throws an error code. The only other way that I might get their attention would be to have it put straight onto the back of a truck when it starts it regen process and send it to them. The trouble with that is my nearest dealer is 80 k's away and I'm already not overly keen on the service dept. as it is. I guess if it eventually *****$ itself then they'll know what the problem is and will be able to fix it, hopefully :duh:

Russ

[chisler]

I've also noticed if I change High, like around 4000, then crusing at 100kmh in 6th puts my rpm around 2000.
though if I change early (automatic mode :???:) then 100kmh in 6th gives about 1500rpm

[Orville]

Howdy all,
I have just driven up to Coffs Harbour and back from Sydney. We found that the car was comfortable in 6th from 90 k upwards and cruised happily with the cruise control on at 100k and above. Our fuel figures were 950 ks for 50 litres (fuel light just on). 6th has more than enough torque from 100 to accelerate, if anything 5th was all I needed for overtaking if I was in a hurry. Sure, blast it up to 4500 in 3rd and 4th for a cleanout every now and again, but 6th was the most used gear in our travels. Using 5th would have definitely used more fuel at 100 kph.

ps - best car I have ever owned and this is number 14, not counting the dozen or so work cars as well.

cheers
Orville:driver: 05 TDI Comfortline

[OvaltoJetta]

I've just done a return trip from Perth to Bendigo plus a bit. On the way back between Balladonia and Norseman - 658 klm - the car was on cruise in 6th and the tacho was sitting on 2400 90% of the way. :eek: The economy was 6.6l / 100.