I've not seen any good MPG fights for a while...

What mpg are people getting these days? How accurate do they find the computer?

With my mods on a 1.9mjet 150 I am now seeing 99.9 on the computer if I drive at a steady 50mph on the motorway and nearer 80mpg combined (though it does drop if I start driving spiritedly)

With the car as standard, the best I could get was 52mpg and more like 40s combined...

I will however need to fill her up again to see what my real world cost per mile / mpg is.

No way you are getting anywhere near those figures, I await with interest your figures when you brim the tank!

What modifications are these?

Tuning box and removing BOTH cats.

Completely standard, I was lucky if I got 470 miles out of a tank. I was seeing nearer 600 before replacing the pre cat - shall let you know what difference that now makes, but deffo higher again.

Obviously if I drive the car hard economy falls away, but I'm finding having a heavy foot with the mods is giving me the same / better economy than frugal driving in a standard car.

Fergie said:

With my mods on a 1.9mjet 150 I am now seeing 99.9 on the computer if I drive at a steady 50mph on the motorway and nearer 80mpg combined (though it does drop if I start driving spiritedly)

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So a full tank will take you 1K miles will it?
(57 litres @ 80 mpg = 1,002 miles)

142201Z

austenw90 said:

What modifications are these?

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Electric motor, and a hamster powered alternator that drinks diesel.

From full till when the light comes on i can usually get 450-470 miles so thats 550-570 miles on a tank of fuel. thats on a standard 165 sport. Worked it out at between 47-51 mpg on a daily comute and drive around town. this as opposed to my last car a Focus ST which did around 28-30 mpg if i was lucky and similar driving.

Caravadossi said:

So a full tank will take you 1K miles will it?
(57 litres @ 80 mpg = 1,002 miles)

142201Z

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I did say that is what the computer is showing

I think it is overly optimistic, but no harm in filling up, doing 20 miles @ 50mph and then filling up again to see what she actually uses.

Main thing is I've seen my real world mpg increase by over 20% which partly offsets the cost of fuel and helps justify some light mods.

Fergie said:

I think it is overly optimistic, but no harm in filling up, doing 20 miles @ 50mph and then filling up again to see what she actually uses.

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To my mind this doesn't really represent the mpg you willl achieve with normal driving. Your test should be either based upon your usual driving to show the real world mpg you achieve or on a long run where you are using a good portion if not all of the tank - say Glasgow to Manchester (as an example). I'm sure that if I drove my 2.0 Multijet 20 miles at 50mph the computer would tell me something like 65mpg (or 55ish possibly real world) however this would not at all represent anything other than driving at 50mph everywhere I went which is never the case so therefore not accurate at all.

Because a tuning box is outside of the ecu the trip computer does not see any additional fuel injected hence the false economy figures, tuning box suppliers will probably not point this out and their customers will believe they have amazing economy. In reality a tuning box might improve economy a bit but not massively

MY real world firgures, and I've left note on fill ups showing what the Trip showed.

http://www.fuelly.com/driver/mep/bravo

Fergie said:

I did say that is what the computer is showing

I think it is overly optimistic, but no harm in filling up, doing 20 miles @ 50mph and then filling up again to see what she actually uses.

Main thing is I've seen my real world mpg increase by over 20% which partly offsets the cost of fuel and helps justify some light mods.

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Well – ya talk-the-talk … but d’ya walk-the-walk?

Q1. What figures have you used for this >20% improvement?

Q2. What are your current black-box read-outs?

Range ………. miles
Distance ………. miles
Av.mpg …….. .. mpg
Inst mpg (not required!)
Av speed ………. mph
Time ………. hrs/min

Q3. On an M-way on diesel fuel – what constant speed gives you better mpg, 50 or 70 mph?

Q4. Given your alleged (i) 99.9 or (ii) 80 mpg – what ml of diesel do you estimate you’ll require for 20 mile @ 50 mph?

Q5. Brim-up & put-up your range read-out.

151105Z

I am going in for a remap from Angel Tuning in the near future and was in a car of similar spec (engine size, BHP, torques mpg etc etc) that had a remap done. He is now getting 210 bhp and also an extra 12% mpg. He has gone from 45-50 mpg up to 53-57 mpg. With DPF removed he might get even more. By the way it wass an Audi S4 2ltr TDi 160 bhp (original spec)

PS The pull oh the machine was frickin awesome.

PPS which by the way doing the maths would be approx 554 - 580 miles between fill up and light coming on

My 2008 Multijet 1.9 8v 120bhp is getting about 50mpg at the moment brim to brim from nearly empty, the on board computer over estimates it by about 3 percent. This is in mixed motorway & town commuting. During the summer I was getting about 53mpg - can't duplicate that in the colder weather. Anyone else seen this degradation?

Brimming it after 20 miles is unlikely to give an accurate figure IMHO

Our delta 165 multijet (pretty much the same as a bravo but slightly bigger and a tad heavier) is averaging about 45 based on brim to brims using an android app, this is about 3 mpg more than the trip shows(!) this is a mix of a few longer trips and town driving but mostly a drive to work of 14 miles which is 75% rural. If I get to do more long runs it would be nearer 50.

madmalc said:

My 2008 Multijet 1.9 8v 120bhp is getting about 50mpg at the moment brim to brim from nearly empty, the on board computer over estimates it by about 3 percent. This is in mixed motorway & town commuting. During the summer I was getting about 53mpg - can't duplicate that in the colder weather. Anyone else seen this degradation?

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Pretty much exactly what I get from mine, only my computer is about 5% optimistic.

madmalc said:

During the summer I was getting about 53mpg - can't duplicate that in the colder weather. Anyone else seen this degradation?

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Yes, it's a big diesel lump which takes a while to warm up. The colder it is the longer this takes.

My 1.6 120 at 11C external temp this morning took a good 6-7 mile to reach full temp and sit there, and stopping in traffic at first with heating on will pull engine temp back down again slightly until upto max and the whole block is warm.

Most Easterly Pandas said:

Yes, it's a big diesel lump which takes a while to warm up. The colder it is the longer this takes.

My 1.6 120 at 11C external temp this morning took a good 6-7 mile to reach full temp and sit there, and stopping in traffic at first with heating on will pull engine temp back down again slightly until upto max and the whole block is warm.

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Used to have a mg ZT with remote control webasto pre heater gonna miss that luxury this winter

Caravadossi said:

Well – ya talk-the-talk … but d’ya walk-the-walk?

Q1. What figures have you used for this >20% improvement?

Simple fact that as standard I was lucky to get 470 miles from a tank. Now I get over 600 and thats reading from the trip only

Q2. What are your current black-box read-outs?

Range ………. miles
Distance ………. miles
Av.mpg …….. .. mpg
Inst mpg (not required!)
Av speed ………. mph
Time ………. hrs/min

Need to check and will post.

Q3. On an M-way on diesel fuel – what constant speed gives you better mpg, 50 or 70 mph?

50mph, but that is a given.

Q4. Given your alleged (i) 99.9 or (ii) 80 mpg – what ml of diesel do you estimate you’ll require for 20 mile @ 50 mph?

If 80mpg were correct, then 20miles = 1/4 of a gallon = 1.1165 litres I believe.

Q5. Brim-up & put-up your range read-out.

151105Z

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