mpg improvement after some miles

[sssstew]

Hi all

Well my thoughts are being confirmed with the more miles i get on my car, its now approaching 50k. Every so often me and emma drive from Milton Keynes to Tavistock in Devon which is about 250 miles of which about 1/3rd is A roads to Swindon and the rest is motorway. I like to drive between 2-3k rpm on the a roads with some full throttle acceleration whenever the overtaking opportunity arises and circa 80 on the motorways.

On the trip down which was done in one go 4hrs 30 mins with roadworks on each road the final mpg was 59.1, and thats not from the computer which said 60.4 by the way.

On the way home with a stop off in bristol i got 56.4 overall.

Each time we do this journey over the last 2 years the mpg has been getting a little better each time.

so people.. get some miles stacked on your cars please!

 

[craig-pd130]

Good stuff!

Last weekend I confirmed the Passat's "sweet spot" -- if I cruise at 2700rpm in 6th (about 85mph) then I get better mpg (about 53-55) than I do at 75mph. Must be aerodynamics or something ...

 

[dmjw01]

Must be aerodynamics or something ...

It's definitely NOT aerodynamics. Drag increases very rapidly as your speed increases - there's no escaping that fact, regardless of the aerodynamic shape of the car. I have, however, read that diesels are at their most efficient when operating at higher power. If that effect is enough to overcome the increased drag at the higher speed then it could explain the improved mpg.

 

[sssstew]

yeah agreed, its the power of the engine which youve found the sweet spot at, 75 must be labouring it a bit, as you have 6 speeds.

 

[muddyboots]

yeah agreed, its the power of the engine which youve found the sweet spot at, 75 must be labouring it a bit, as you have 6 speeds.

75 is fine in the Passat, the Ibiza had a much taller 6th gear (but still wouldn't have been labouring at 75).

Actually the gearing of the Passat seems quite handy, seem better ratios for acceleration than the Ibiza but at the expense of higher RPM when cruising. I've been pleasantly surprised how well the barge accelerates, I reckon when Upsoluted it won't be far off my Ibiza.

I always thought the Ibiza had a "sweet spot" around 80mph in 6th.

Stew, do you reckon the Passat mpg will improve as I climb through the 90ks

 

[Robdrums]

That's good, I'm hoping to see an improvement in my MPG, I average about 50-52 on a motorway journey, and 40 round town if I'm fairly sensible, as low as 34 if I drive hard, in a 150 FR Leon. Which I think is improveable.

Rob

 

[sssstew]

lee - i dont think it will get much better, generally 80k is where it peaks at and afterwards stays stable as the engine has run in properly.

robdrums - how many miles on it?