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[Humpy]

Not really a problem more of a statement really.

Went down to Somerset from Kent last weekend in SWMBO's car a 3.0 auto saloon. Without trying I got 35mpg whereas the same trip in my car (3.0 manual est) I struggle to get 28mpg and that's really trying! One thing I did notice is that my car does 3500rpm at 70 whereas the wifes car does 2500rpm at 70! That would probably explain it. I'm guessing that a manual estate is geared a lot lower to cope with load lugging? And there's me bought a manual 'cos I though it'd be more frugal  Can anyone confirm the difference in gear ratios?

Humpy

[Kevin Wood]

3500rpm at 70 sounds rather high. Makes me wonder if it's got the right diff ratio.

Gear ratio information here http://www.autobahnstormers.org/eligible_cars/omega_b/mv6.asp seems to suggest you should be geared for 24.9 MPH/1K RPM. As it is you're only getting 20 MPH.

Kevin

[tigers_gonads]

has it been a 2.5 then converted too a 3 ltr ?

i know the 2.5 dif is lower geared

[Welung666]

Is it ex-cop? Or could it have an LSD fitted from an ex-cop?

[tunnie]

3.5k rpm at 70mph is way to high, even my 2.2 is sub 3k rpm at 70, its only at 3.2k rpm at 80mph

[Humpy]

Interesting replies chaps. As I had the car after umpteen owners I don't know where it came from originaly but I don't think it was a police car as it has all the toys, roof rails and no holes everywhere   I don't think it's got a slipper as I've driven these in the Monza's and it don't feel the same and as far as I know it's always been a 3.0l so gawd knows what the problem is.
Looking at the data on the ABs site, the manual is lower geared but no mention if the estate is even lower.
Like I said, I went for a manual as I thought I was doing the right thing (and it was the right price and only 2 miles away from home ) but now I'm not so sure

Humpy

[VXL V6]

AFAIK there is no difference in gearing of identical engine/gearbox combinations between estates and saloons.

[MickAP]

Daft as it sounds but....did you use 5th gear.

I've been driving my auto around for 2 weeks so never touched the manual estate in that time.

Went on a long journey in the estate and did around 25 miles before I realized I'd not got it into 5th gear, that's doing 70mph with c/c on.
Made a bit difference to mpg and of course rpm shifting up from 4th to 5th

Never done that before...forgot I had a 5th gear


Mick

[Johna]

I've got a 2.6 manual and just bought the missus a 2.6 auto. Identical cars, year, trim etc other than that, and strangely enough I noticed the auto was getting more mpg's when cruising at 70. I thought I was going round the bend  Maybe not then? 

And I was sure it was running slightly less revs, but haven't been allowed near it again to double check against mine properly.

[Humpy]

Definately using 5th gear, you'd know all about it if not! The mystery deepens...

Humpy

[Kevin Wood]

Is it worth double checking the speedo is accurate against a GPS? (If only to protect your licence? )

If it is reading OK, only thing I can think of is that the diff ratio is wrong. You can work it out by getting under the car and turning the two output shafts together through one revolution while an assistant counts the turns of the propshaft.

On the plus side, it must accelerate like a scalded cat.

Kevin

[Humpy]

On the plus side, it must accelerate like a scalded cat.

It doesn't hang about

Humpy

[jonnycool]

On the plus side, it must accelerate like a scalded cat.

It doesn't hang about

Humpy

1st gear must be very short though  

[revolvolt]

just a quick thought but your wheels and tyres are the right size? that could change gearing

[Sixstring]

I've had both the 3.0 V6 manual and now the auto, DEFINATELY more frugal with auto, but less acceleration/sporty/lower cruising revs at 80mph.
hope this is some help.

Mike.