Cruising at 60+ mpg @ 60 mph

[deejaaa]

your results are impressive, esp for a gasser.
the last fill-up gave me 58.8 mpg, calculated. the ultragauge gave me aroung that(but i always calculate anyway) but mph is not calculated right so i mostly use it for the instant mpg. besides airing up, front tires, this is from driving style.
i will be working on a rear belly pan in the next 2 weeks. i like to re-use so i tore down a gas water heater and will be using the outer sheet metal.
rear tires are next/at the same time. using Cooper CS4 195/65/15-91T, 80,000 wear rating on the front and getting very good results.

[bitmap]

Hello, I don't want to hijack this thread, but I would like to know your opinion on my MPG.

Yesterday I came back from 1700miles round trip with my slightly modified Skoda Octavia 2.0 TDI (VW Golf Variant clone).
I drove mainly at highway with cruise control set at 68.35mph (110km/h) indicated, no AC, no hypermiling techniques except coasting down the hills in neutral.

With some country lanes driving at 55MPH speed limit, villages, toll booth queues etc. i managed to get 57.17 (92km/h) average speed and about 58MPG total.

Is that a good result for diesel engine and this average speed? What do you think?

[PressEnter[]]

I'd say that's pretty good. I'd expect about the same from my car, which I think has the same engine. Does it also have the same 6-speed manual as a VW? Though if you managed that with a DSG I'd really be impressed.

[bitmap]

Yes it has 6 speed manual but being a 2008 model it has stupidly short 5th and 6th gears. It turns 2000rpm at 110km/h indicated. Newer models have much more sensible gearing.
It,s also PD engine not CR. In nonRS Octavia models, CR was not available until 2010.

[Frank Lee]

1,243 ft/mn piston speed @ 2000 rpm isn't out of whack... at least for a gasser. I don't recall optimum range for four stroke diesels.

The shorter the stroke the higher the rpm while still having efficient piston speeds.

[PressEnter[]]

The 2.0 PD is definitely more efficient than the CR, but I guess the gearing evens things out at that speed. I don't get to 2000 RPM until 75 mph.

[bitmap]

Fuel economy wise, 2.0 tdi PD is the worst four cylinder diesel VW ever made.
According to NEDC, my car is supposed to get 50MPG extra urban and 42,7 combined.
Same car with 2 litre CR engine has NEDC rating of 58,7 extra urban and 48 combined.
That is with better gearbox, but CR engines are much more fuel efficient that old PDs especially 2 liter version.

Took me a lot of time to get where I am, but now reading about petrol engined Honda getting almost 60MPG at 60mph got me thinking if I shouldn't be doing much better

[California98Civic]

64.02 mpg on the just completed tank (probably would have been 66.5 if I had stayed with my usual pump/station).

I drive this car a lot more on the freeway now, which was part of the reason for the transmission swap. I wanted the option without having to drive 50mph to keep rpms down. The taller gearing of thei 1993 CX transmission is amazing on the freeway, and on some of the secondary roads too. I'll drive some of the secondary roads before hitting the freeway at 40-45 mph in 5th gear, turning merely 1300 rpms maybe and getting anything from 70-100mpg readings on my gauge, depending on load (27%-33% or so). Warms the car up for the freeway.

I love the transmission swap, now I just have to get into rebuilding the old DX tranny with a kit and the VX final drive I bought an age ago so I can have a backup...

james

[euromodder]

Originally Posted by bitmap

Fuel economy wise, 2.0 tdi PD is the worst four cylinder diesel VW ever made.

Dunno if it was their worst, but the earliest 2L TDi was definitely a step back compared to the 1.9L TDi regarding fuel efficiency.

[bitmap]

Yes it was. And 1.9 PD was a step back compared to 1.9 VE
But it's not all engine's fault. As I recently found out 6 speed transmission which comes with 2l engines is much more "draggy" than either 5 speed that came with 1,9 PDs or earlier 6 speed 'boxes.