Best MPG on Motorway...

**Dane-10** · 9th January 2013, 22:38

Over the past couple of days ive done some motorway miles, and have started to notice that im getting a better MPG in 5th Gear @ 70mph over 6th gear @ 70mph.

Whats the point in 6th gear when there is a speed limit of 70 and that gear doesnt do as good MPG as 5th.

Its in a 1.9 cdti (remapped)

5th gear sits at around the 2400rpm, and 6th sits around 1900rpm for 70mph.

Any one else noticed this?

**paulvectrac** · 9th January 2013, 22:40

50 in 6th 90.2 mpg lmao

**Derek Mc** · 9th January 2013, 22:47

Over the long run 6th does give better returns as the engine is turning slower hence using slightly less fuel, I can manage 58mpg on my daily 100 mile commute keeping to the limit in 6th on clear runs, and am on an average of 53.2mpg on the last 180 gallons used including city country m/way and congestion driving in rush hour

**Dane-10** · 9th January 2013, 22:58

Mine really wouldnt like 50 in 6th what so ever. Would near enough be ticking over!!!! haha Got me confused now, why mine is like this. I did 100 miles today and i was doing 58mpg with some motorway and town driving. which im happy with, just find it odd on the motorway i can get a better MPG in 5th than 6th at 70mph

**BYGino** · 9th January 2013, 23:02

Originally Posted by paulvectrac

50 in 6th 90.2 mpg lmao

Not for me LOL 50 in 6th = 32MPG tops (2.8 Auto) time to go back to diesel I think!

**veclee** · 9th January 2013, 23:33

Best mpg is only achieved on the back of a rac wagon lol and you can have a kip with out worries

**Chris SRi** · 10th January 2013, 08:32

Maybe you need to go faster than 70mph for the engine to have enough torque in 6th to keep you going while getting good economy?

You might be labouring the engine if its like that.

By no means an expert, but could your car be suffering from low end power?

**Chris SRi** · 10th January 2013, 08:33

Oh- and about 50mpg in my 1.8 VVT doing 70mph at just under 3000rpm.

**Derek Mc** · 10th January 2013, 08:57

The 1.9 CDTi works at it's best over 1500rpm and on the motorway 70mph is right in the middle of the powerband for the engine. I think if you repeat the test a couple of times on the average economy 6th will always prove more economical than 5th mile for mile.

**Dan_BlackSRi** · 10th January 2013, 10:39

Originally Posted by Chris SRi

....but could your car be suffering from low end power?

That's not a bad shout.

I have found that 67mph in 6 gives me the best economy on the motorway, I can easily achieve mid 60's doing that (mine is mapped too).