Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: mrjimbo on 19 July 2010, 14:35:30
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What is the most economical cruising speed for a 3.0 V6 Estate ?
Yesterday i went from Didcot to Andover and back, all dual carriageway and Aroad (A34, A303 and A343). Round trip of 102miles at a steady 75mph and 50mph on A road and it used 21.65 litres (brimed at start and again at finish) which works out to be 21.05 mpg >:(
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That isn't right....were you pulling an ocean liner behind you.
Best economy for my 3.0 is about 80 for which I return around 32 mpg ave.
Combination of around town and dual carriageway, I never sink below 25 mpg ave.
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What is the most economical cruising speed for a 3.0 V6 Estate ?
Yesterday i went from Didcot to Andover and back, all dual carriageway and Aroad (A34, A303 and A343). Round trip of 102miles at a steady 75mph and 50mph on A road and it used 21.65 litres (brimed at start and again at finish) which works out to be 21.05 mpg >:(
You don't mention if you have an auto or manual, but if I remember correctly, on those roads the box is having to change up and down in a way that does not happen when cruising on a motorway. Your mpg will then obviously be reduced.
I certainly find that if I can cruise steadily on a motorway at 80 mph I am returning up to 35 mpg. However, if encountering A roads mine certainly falls to nearer 21-25 mpg, depending on road congestion. Overall I usually return about 22 mpg at best when including town travel. Mines an auto, so if yours a manual, dependending on how you drive, you will return slightly better returns;) ;)
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I would imagine the wind and temperature can play on the overall figure but that is poor.
I would have expected a min of 25 mpg.
Yours actually rurned 21.42
Has the car been regulaty serviced and where the tyre pressures correct.
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I certainly find that if I can cruise steadily on a motorway at 80 mph I am returning up to 35 mpg. However, if encountering A roads mine certainly falls to nearer 21-25 mpg, depending on road congestion. Overall I usually return about 22 mpg at best when including town travel.
That's not far off what I average with the 2.5TD! I'm starting to wish I'd bought the 3.0 now, given how much cheaper petrol is vs. diesel..
There's a nice one in white on Autotrader, too.. only £100 more than I paid for the tractor. </drift>
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I certainly find that if I can cruise steadily on a motorway at 80 mph I am returning up to 35 mpg. However, if encountering A roads mine certainly falls to nearer 21-25 mpg, depending on road congestion. Overall I usually return about 22 mpg at best when including town travel.
That's not far off what I average with the 2.5TD! I'm starting to wish I'd bought the 3.0 now, given how much cheaper petrol is vs. diesel..
There's a nice one in white on Autotrader, too.. only £100 more than I paid for the tractor. </drift>
Well I certainly don't spare the horses when driving, with an enjoyment in using the 'S' mode and hard kick downs as required. I should add I only get about 19mpg around town :D :D ;)
There is only one diesel I would go for and that is the Merc E class 320 CDi; all other diesels in my experience are noisey, slow, and lack response. I would certainly go for a nice 3.0 petrol if you see one that takes your fancy! :D :D ;) ;)
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I certainly find that if I can cruise steadily on a motorway at 80 mph I am returning up to 35 mpg. However, if encountering A roads mine certainly falls to nearer 21-25 mpg, depending on road congestion. Overall I usually return about 22 mpg at best when including town travel.
That's not far off what I average with the 2.5TD! I'm starting to wish I'd bought the 3.0 now, given how much cheaper petrol is vs. diesel..
There's a nice one in white on Autotrader, too.. only £100 more than I paid for the tractor. </drift>
Well I certainly don't spare the horses when driving, with an enjoyment in using the 'S' mode and hard kick downs as required. I should add I only get about 19mpg around town :D :D ;)
There is only one diesel I would go for and that is the Merc E class 320 CDi; all other diesels in my experience are noisey, slow, and lack response. I would certainly go for a nice 3.0 petrol if you see one that takes your fancy! :D :D ;) ;)
My chipped TD is smooth, quiet, and certainly does not lack response, it surprises many beemers at the lights. ::) ::) ::)
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It's an auto :y
On the dual carriage way it was a steady 80-85mph no real slowing then speeding up and the A road was the same a steady 50-55mph again no real slowing or speeding up, only slowed to around 20mph on the A road to let cars turn right twice and the junctions A road-dual carriageway-Aroad were all free flowing and only stopped at one set of roadworks for about 30sec as came back into Didcot on the way home.
The outward journey was at 07.30 and the roads were pretty much deserted and the homeward journey was at 19.00 and although the roads were quite busy the outside lane on the dual carriageway was maintaining a steady spead of between 70-85mph all the way home.
When i first had the car i went from Didcot to Knockhill in Scotland and back driving at a steady 80-85mph and returned 33mpg so i don't know whats going on now.
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It's an auto :y
On the dual carriage way it was a steady 80-85mph no real slowing then speeding up and the A road was the same a steady 50-55mph again no real slowing or speeding up, only slowed to around 20mph on the A road to let cars turn right twice and the junctions A road-dual carriageway-Aroad were all free flowing and only stopped at one set of roadworks for about 30sec as came back into Didcot on the way home.
The outward journey was at 07.30 and the roads were pretty much deserted and the homeward journey was at 19.00 and although the roads were quite busy the outside lane on the dual carriageway was maintaining a steady spead of between 70-85mph all the way home.
When i first had the car i went from Didcot to Knockhill in Scotland and back driving at a steady 80-85mph and returned 33mpg so i don't know whats going on now.
All I could suggest is that your car may need a good service, with the breathers given a thorough clean through. ;) ;)
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Spent the weekend before last changing gearbox oil, cleaning breathers and checking that there were no vacum leaks and sorting multirams. Oil changed less than 1k new plugs fitted at same time along with oil filter and air filter, no misfires and the multirams were checked on Saturday at Oxford with the Tech2 (TheBoy) and given a clean bill of health.
All seems to be well but not happy with 21/22mpg though >:(
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Mr J, your speeds quoted between the original post and the recent one have increased by up to 10mph ;) Did you use cruise or was it foot controlled?
I filled up with LPG at Honnington last weekend, travelled to Plymouth (with a very small amount of town use) and came back to Suffolk via M5, M42, M6, A14. Set the cruise to an indicated 80 and let it do it's work (so lots of throttle on hills) with the occasional burst of higher speed for safe overtaking and returned an average of about 31/32 mpg IIRCC.
FWIW, I feel that an indicated 80 is the best compromise between getting on with it and economy. Much more and the economy starts to really suffer. Interestingly, at 70/75 the economy isn't dramatically better, perhaps 2-3 mpg at 75, 6-8mpg at 70.
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What is the most economical cruising speed for a 3.0 V6 Estate ?
110? ::)
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Mr LD
It was on the Cruise Control mostly and set at 85mph on the dual carriageway and 50/55mph on the A roads on the way there, and on the way back on the Cruise Control mostly set some where between 70 and 85 mph depending on the flow of traffic and 50/55mph on the A roads.
I've always found it to be most economical at between 80 and 85mph on a run, I managed the 33mpg going to Knockhill and back with ocasional bursts at 85+mph and i quite often tow a car trailer with a Mk1 Escort on the back and usually get 24/25 mpg on motorway and dual carriageways without even trying so i'm a bit puzzled as to what was occuring on Sunday. I'll keep an eye on it over the next week or so and see if it's a one off or if it continues at 21/22mpg :y
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something not right imo. Has the multiram issue returned possibly? Also concider cam belt timing, blocked exhaust etc
I presume The Boy did a full diagnostic? Checked fuel trims etc?
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As Chris says, keep an eye on it. It could quite simply be atmospheric conditions (although I feel that it was too much of a difference to be just that) or that more throttle was used than you recall. Keep an eye on it IMO :y
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The most economical cruising speed for any car is the slowest you can go in top gear, anything above this and you are wasting energy on air resistance. if you can get behind a large vehicle so that you can slipstream, all the better.
80 mph would never be considered an economical speed to be travelling at; even if you reduced your speed to 70mph you'd be using significantly less fuel
Jon
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The most economical cruising speed for any car is the slowest you can go in top gear, anything above this and you are wasting energy on air resistance. if you can get behind a large vehicle so that you can slipstream, all the better.
80 mph would never be considered an economical speed to be travelling at; even if you reduced your speed to 70mph you'd be using significantly less fuel
Jon
Agreed, except that the engine speed needs to be high enough for it to be working efficiently. Normally the bottom end of the torque delivery is best so 2K RPM or a little higher for the V6. Any slower and the engine is labouring. It may have fewer losses in terms of friction but it won't be burning fuel as efficiently.
Mine certainly drinks more fuel as speeds raise. 36 MPG at 60/65, 33 at 70, 28-30 at 80 and so on.
I've never survived the boredom of driving slower than 65 to get a meaningful reading - sorry. ;)
Kevin
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I find judging throttle off but not breaking helps, ie don't stay on the power all the way to the junction and break hard ish. Rather throttle off early using the auto boxes tendency to roll on with minimal engine braking, and hence minimal fuel, and judge it to give minimal braking effort when at the junction. Keeps me amused when I can't crack on due to traffic, then waste it all when the road clears. ;)
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Completely agree with Chrisgixer...Thats how i drive my 3.0 and in fairness she delivers better mpg than my previous 2.5.
Combo between dual carriageway and town driving for work, never drops below 25 on ave.
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Completely agree with Chrisgixer...Thats how i drive my 3.0 and in fairness she delivers better mpg than my previous 2.5.
Combo between dual carriageway and town driving for work, never drops below 25 on ave.
That's how I was driving following TheBoy and Chrisgixer on Saturday, as my Trade Club brake pads felt like blocks of wood. ::) :-X
Kevin
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Completely agree with Chrisgixer...Thats how i drive my 3.0 and in fairness she delivers better mpg than my previous 2.5.
Combo between dual carriageway and town driving for work, never drops below 25 on ave.
That's how I was driving following TheBoy and Chrisgixer on Saturday, as my Trade Club brake pads felt like blocks of wood. ::) :-X
Kevin
Oe pads Kev, little dust good feel, no squeak, and I'm told will last much longer than tc pads...no fade on saturday. I presume your tc pads are a little thin?
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Completely agree with Chrisgixer...Thats how i drive my 3.0 and in fairness she delivers better mpg than my previous 2.5.
Combo between dual carriageway and town driving for work, never drops below 25 on ave.
That's how I was driving following TheBoy and Chrisgixer on Saturday, as my Trade Club brake pads felt like blocks of wood. ::) :-X
Kevin
Oe pads Kev, little dust good feel, no squeak, and I'm told will last much longer than tc pads...no fade on saturday. I presume your tc pads are a little thin?
Nope. Not been on there that long (although probably longer than I think TBH).
Everyone in both kit car and MX5 circles seems to rave about Mintex 1144 pads. £98.20 inc.VAT an axle set for an Omega though. :(
Kevin
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two issues - is it auto ? and what diff has it got.
I have two similar cars, as follows.......
MV6 3.0 estate ex-plod auto with 4.22 LSD - manages just over 20mpg at best
Elite 3.0 manual - standard diff - can't get it below 30mpg
yours is ex-plod I'm certain, so check the diff out. If you're not sure, then record the speed you're doing at 3000 revs in top (satnav), send me a pm with your tyre size and I'll calculate it for you.
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Sorry i haven't replied before but been without PC for last 24hrs :(
two issues - is it auto ? and what diff has it got.
I have two similar cars, as follows.......
MV6 3.0 estate ex-plod auto with 4.22 LSD - manages just over 20mpg at best
Elite 3.0 manual - standard diff - can't get it below 30mpg
yours is ex-plod I'm certain, so check the diff out. If you're not sure, then record the speed you're doing at 3000 revs in top (satnav), send me a pm with your tyre size and I'll calculate it for you.
It is indeed ex plod but the issue isn't diff related as i have achhieved 32/33mpg in the past driving in exactly the same way.
Posted by: chrisgixer Posted on: Yesterday at 06:53
something not right imo. Has the multiram issue returned possibly? Also concider cam belt timing, blocked exhaust etc
I don't think the multiram problem has returned as it seems to be driving OK and doesn't seem to be holding back or slugish at all so i doubt the exhaust is blocked, though i could be wrong. As for the cam belt/timing, last time i had problems with the belt it ran like a dog but it seems to be smooth enough at the moment.
I'll have a check of the exhaust and cambelt at the weekend and report back :y
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If when i check the cambelt at the weekend would it be OK to alter the cam timing if i find it's not spot on without doing a full cambelt change ?
It was 2years and 12000miles since it was last done :y
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If when i check the cambelt at the weekend would it be OK to alter the cam timing if i find it's not spot on without doing a full cambelt change ?
It was 2years and 12000miles since it was last done :y
Ah, thought the cam belt had been done recently, appologies. If your getting variation in fuel economy, as opposed to continually poor, then not likely to be cam belt unless there is something very wrong, in which case the belt would have failed by now. Was it set correctly with a locking kit? No need to change the belt if adjusting.
Did The Boy run a full diagnostic at oxford? What was the fuel trim error? (although I'm sure he would have said if there was a problem) :-/
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The cambelt was set as per instructions and used a locking kit which i borrowed from a friend of a friend so as said probably not a cambelt issue.
TheBoy only lowered the idle speed down to factory setting as plod had raised it(probably due to alternator not coping with all the equipment at idle ?) and checked the multirams were functioning, which they are now after unpluging them several times (probably dirty plug coonection). I don't think he did anything else, I'm sure he'll be along soon to confirm :y
It seems to drive OK with nothing untoward but i just can't get my head round why i only got 21mpg on Sunday.
I have in the last couple of weeks changed the Autobox fluid, cleaned the breathers, removed the plenum to check the 'O'rings were sound, sorted the multirams, changed the antifreeze, had the aircon HP service valve changed and regassed. The brakes aren't binding and there's no vacum leaks(Vacum tank will retain vacum for 24hrs+) and the exhaust isn't heavily sooted either. It's a mystery at the moment but i will get to the bottom of it :y
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The cambelt was set as per instructions and used a locking kit which i borrowed from a friend of a friend so as said probably not a cambelt issue.
TheBoy only lowered the idle speed down to factory setting as plod had raised it(probably due to alternator not coping with all the equipment at idle ?) and checked the multirams were functioning, which they are now after unpluging them several times (probably dirty plug coonection). I don't think he did anything else, I'm sure he'll be along soon to confirm :y
It seems to drive OK with nothing untoward but i just can't get my head round why i only got 21mpg on Sunday.
I have in the last couple of weeks changed the Autobox fluid, cleaned the breathers, removed the plenum to check the 'O'rings were sound, sorted the multirams, changed the antifreeze, had the aircon HP service valve changed and regassed. The brakes aren't binding and there's no vacum leaks(Vacum tank will retain vacum for 24hrs+) and the exhaust isn't heavily sooted either. It's a mystery at the moment but i will get to the bottom of it :y
That's the spirit Jim. Wish we had paid more attention at oxford now. :-/
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The car seems to drive OK so there didn't appear to be anything that needed to be looked at other than the idle speed and check the multiram solenoids were working as they should, and they were given a clean bill of health :y
21.4mpg on a run ain't good though so im going to check the cam timing and exhaust for blockages as you suggested.
Anyone got some pictures of the timing marks on the cam wheels and which marks are the right ones ?
I've lent my "book of lies out" and won't be able to get it back until Tuesday and i won't be able to get a Cambelt DVD in time for Saturday.
I've got a locking kit :y
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Completely agree with Chrisgixer...Thats how i drive my 3.0 and in fairness she delivers better mpg than my previous 2.5.
Combo between dual carriageway and town driving for work, never drops below 25 on ave.
That's how I was driving following TheBoy and Chrisgixer on Saturday, as my Trade Club brake pads felt like blocks of wood. ::) :-X
Kevin
Oe pads Kev, little dust good feel, no squeak, and I'm told will last much longer than tc pads...no fade on saturday. I presume your tc pads are a little thin?
Hmmm, I was on TC cheapo pads, no issues at all here. I agree cheapo TC pads are dusty (esp the rear if you make a lot of use of TC ::)), but nothing we did on Sat should have caused any issues for any pad :-/
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Drivers side
(http://i267.photobucket.com/albums/ii316/mrjimbo-2008/omega%20cambelt%20timing/Omegacamtiming001.jpg)
Passenger side
(http://i267.photobucket.com/albums/ii316/mrjimbo-2008/omega%20cambelt%20timing/Omegacamtiming002.jpg)
I have just finished checking the cam timing and found the passsenger side bank to be approximately 3/4 tooth advanced so i've adjusted it back to where it should be using the locking tool and all seems OK, no sign of anything untoward found, more likely an error when cambelt was changed.
Would that small timing error cause the 21.4mpg though ?
Can't find anything wrong in the exhaust department either.
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quick question, does your gear box have an overdrive? if so is this working as it should? also is the gearbox fluid level right? apologies if these have been checked already. :-/
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Drivers side
(http://i267.photobucket.com/albums/ii316/mrjimbo-2008/omega%20cambelt%20timing/Omegacamtiming001.jpg)
Passenger side
(http://i267.photobucket.com/albums/ii316/mrjimbo-2008/omega%20cambelt%20timing/Omegacamtiming002.jpg)
I have just finished checking the cam timing and found the passsenger side bank to be approximately 3/4 tooth advanced so i've adjusted it back to where it should be using the locking tool and all seems OK, no sign of anything untoward found, more likely an error when cambelt was changed.
Would that small timing error cause the 21.4mpg though ?
Can't find anything wrong in the exhaust department either.
Can you take pics but this time with the timing tool in place? The cutouts in the rear camcover don't really mean anything, its just an approximation
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Too late, it's all back together ;D
Thats the best i could get of the passenger side bank straight on because the bulb in the aircon pipe is in the way but the locking wedge (red one) wouldn't go in like that but it would when the idler between L and R banks was loosened and adjusted. Tensioned it all back up again and turned it 2 full rotations and both wedges would fit rechecked tensioners and turned it 2 full rotations again and it all lined up again and the wedges fitted.
Now both exhaust cams line up perfectly with the mark on the backplate but the inlet cams line up slightly off the mark on the backplate ( both pointing slightly towards the "V") The wedges wouldn't fit with the cams timed to the inlet marks so i would say it was timed up right now.
It now sounds a bit differant when started from cold, before it used to sound "heavy" on the passenger side as if the passenger side centre box was blowing but there was no leak at the flange where it joins the cat or in the centre box and the back box is good aswell. The heavy sound has gone and the revs seem to settle down to idle a bit quicker too.
When you drive it in "D" through the gears the TC seems to lock-up at 48mph as it did before but before it used to feel "heavy" like it was locking-up to soon and labouring but that is much improved aswell.
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Too late, it's all back together ;D
Thats the best i could get of the passenger side bank straight on because the bulb in the aircon pipe is in the way but the locking wedge (red one) wouldn't go in like that but it would when the idler between L and R banks was loosened and adjusted. Tensioned it all back up again and turned it 2 full rotations and both wedges would fit rechecked tensioners and turned it 2 full rotations again and it all lined up again and the wedges fitted.
Now both exhaust cams line up perfectly with the mark on the backplate but the inlet cams line up slightly off the mark on the backplate ( both pointing slightly towards the "V") The wedges wouldn't fit with the cams timed to the inlet marks so i would say it was timed up right now.
It now sounds a bit differant when started from cold, before it used to sound "heavy" on the passenger side as if the passenger side centre box was blowing but there was no leak at the flange where it joins the cat or in the centre box and the back box is good aswell. The heavy sound has gone and the revs seem to settle down to idle a bit quicker too.
When you drive it in "D" through the gears the TC seems to lock-up at 48mph as it did before but before it used to feel "heavy" like it was locking-up to soon and labouring but that is much improved aswell.
.. but the marks on the backplate aren't very accurate. The proper tool for setting the timing fits onto the front of the sprockets and has accurate markings.
Kevin
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Approx 80 mph seems to be the best on my 3.0 estate, best mpg attained then, between 30-33 mpg on a motorway.
Around town, 30-50 mph variable, 22-26mpg max.
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Right, just a little update.
I used the car on Saturday and did a journey of 69.2miles, all dual carriageway and A roads. Car was kept to 70mph on dual carriageway on the cruise control and a steady 50mph on the A roads, mostly on the cruise control, kept on the move all the time, no stopping for queueing traffic or stopping at traffic lights etc, only 3 roundabouts each way.
Brimmed the tank at the start and again at the end of the journey at the same petrol station using the
same pump and stopped refueling on first click of the nozzle and still only managed 24.54mpg
Used to get 25mpg towing a trailer with a car on without even trying, somethings not right but i can't find anything obvious.
If it keeps on like this, it'll have to go :-[
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the optimum cruising speed if you want to take the risk is actually 56mph... you are likely to see many forms of hand signals and hear a lot of colourfull phrases but you will get the best fuel return......
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It's an auto :y
On the dual carriage way it was a steady 80-85mph no real slowing then speeding up and the A road was the same a steady 50-55mph again no real slowing or speeding up, only slowed to around 20mph on the A road to let cars turn right twice and the junctions A road-dual carriageway-Aroad were all free flowing and only stopped at one set of roadworks for about 30sec as came back into Didcot on the way home.
The outward journey was at 07.30 and the roads were pretty much deserted and the homeward journey was at 19.00 and although the roads were quite busy the outside lane on the dual carriageway was maintaining a steady spead of between 70-85mph all the way home.
When i first had the car i went from Didcot to Knockhill in Scotland and back driving at a steady 80-85mph and returned 33mpg so i don't know whats going on now.
I can't speak for the 3 litre as I have the 2.5. But I find that reducing my cruising speed from the mid eighties to the low seventies makes an enormous difference - high 20s to low to mid 30s in mpg.
And it's obvious why you got better consumption travelling south - it's downhill!!
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When i had problems with the cambelt a couple of years ago the local garage couldn't get to the bottom of the problem and i eventually had to sort it myself. In there attempts to find and sort the problem they had several attempts at diagnosing the problem using electronic diagnosis tools and had a couple of mobile electronic "experts" look at it as well, it was also sent to Gurney's at Benson twice who also failed to diagnose the problem with thier Tech2 and i'm begining to wonder whether in all thier messing about with things they didn't understand they reset something in the hope that it would cure the problem.
Is it possible that they altered the Fuel Trim while they were looking for a cure ?
The thing was running very rich at the time and alsorts of things were changed, MAF sensor, Air temp sensor next to the MAF, Coil pack, HT leads, Plugs, Crank sensor etc al to no avail. As a last resort i took it to my mates barn and decided to start striping everything out looking for the problem and thats when we found that the cambelt had slipped due to the bottom R/H idler/adjuster wheel had been put on back to front when plod last changed it, the cambelt had supposedly been checked by the local garage but obviosly hadn't. Cam belt kit was fitted and normal running was returned.
I had never bothered to check the MPG since then until recently as i haven't done any real journeys in it. Before the cam belt issue i could get 25mpg pulling a trailer with a Mk1 Escort race car on it (Didcot-Lydden Hill- Didcot) without even trying but as i haven't been there since then i hadn't bothered checking mpg but i'm now getting less mpg without the trailer and race car.
Could the fuel trim have been altered or interferred with to mask the problem ?
Could it be something like the Purge valve or Carbon canister at fault ?
Any other suggestions ?
Driving everywhere at 56mph is not really an option, I was getting 33mpg driving on motorways and dual carriageways at 75mph before, now getting 24/25mpg.
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split hose to purge valve can cause same symptome, or indeed any of the four hoses at the back of the plenum.
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I've checked the hoses at the back of the plenum and they all seem OK