new member, oxford uk; diesel honda civic

[RustyLugNut]

Originally Posted by rob.e

Update:
I've booked for engine remap, should be mid-september i get this done.

The map runs the engine slightly leaner on part throttle (cruising) so i'm hoping to see a benefit.

Other positive of the map is it'll get me 309 ft lbs torque (418 Nm) if i need it, should make it pretty nippy i expect

leaning a diesel at part throttle. It's throwing me.

I didn't know Honda made a diesel. Honda quality engineering directed at a diesel power pack sounds like a win to me.

[Xist]

That is a beautiful car that I wish we had here, although it is far too new for me to consider. How often do you use the cargo carrier? Would it be possible to use a tow hitch-mounted cargo box instead? I am not sure how well that would work with your hatch, but that would fill the wake, instead of increasing drag.

Also, I am sure the guys here would say the cargo box would be more aerodynamic the other way.

Has anyone boat-tailed a cargo box?

[rob.e]

Originally Posted by Xist

That is a beautiful car that I wish we had here, although it is far too new for me to consider. How often do you use the cargo carrier? Would it be possible to use a tow hitch-mounted cargo box instead? I am not sure how well that would work with your hatch, but that would fill the wake, instead of increasing drag.

Also, I am sure the guys here would say the cargo box would be more aerodynamic the other way.

Has anyone boat-tailed a cargo box?

Hardly ever use the box tbh. Only when absolutely necessary.. it does make a difference to the economy but not a massive amount, less than you would have thought. The Thule box is a good aero design but yes i think you are right either a box tail or turning it around might be better.

[rob.e]

Update: REMAP.

I've had the car re-mapped a few weeks ago - this is a very common thing for diesel drivers in the uk to do, lots of aftermarket companies offering a re-flash to give you a map that normally just focuses on adding fuel and allowing more boost (= more power).

I found a company that offered a map that also considers the efficiency on low/part throttle and aims to improve on the factory settings.

It's much smoother with the new map, general driving its a nicer car to drive. Full boost is much stronger and it picks up speed much better than before (and uses more fuel as a result) but when i'm driving eco to the max it is much easier to get higher MPG numbers than i was before.

It's now easier than it was before to get in the 70s mpg on my commute. Best i've seen was one motorway (freeway) stretch a couple of weeks ago that was constrained by traffic and speed cameras to 50mph. Over around a 20 mile stretch i got up to 100 mpg which is the best i've seen on this car. It dropped back down after this section but the trip was still 85ish mpg over 150 mile route.

Next i've got some aero tweaks i want to make; grille blocker, diffuser and wheel covers - i'll get going on those mods in the next few weeks.

[cRiPpLe_rOoStEr]

It looks better than the sedan. BTW have you never considered trying supplemental water injection or some dual fuel Diesel + LPG setup?

[rob.e]

Originally Posted by cRiPpLe_rOoStEr

It looks better than the sedan. BTW have you never considered trying supplemental water injection or some dual fuel Diesel + LPG setup?

yes i've done some research but as this is my daily driver i don't have the luxury of taking this off the road to do any development work.. there don't seem to be any off-the-shelf kits for lpg into diesel and i don't want to do any damage experimenting.

i'm sure there are gains to be made with lpg - from what i've read it works in a diesel a bit like nitrous in a petrol (gas) engine - ie makes more power. i don't want a faster car but maybe could be configured somehow to give my economy gains..

[rob.e]

So i've been doing some experimentation, just to see what's possible to achieve for mpg on this car.

Not a scientific test, but seeing how far i could travel on 1 gallon of fuel.

Method:
- re-set the "A" trip meter
- drive until the trip meter and the mpg hit the same number, so in theory this is how far i've gone on one gallon.

i managed a good early morning run earlier this week, starting with a warm engine, clear-ish roads, +8 degrees, dry, some trucks around which pretty much matched for speed, so 56-60 mph. Just one 5 minute mid-way stop/ start i had to do but otherwise a single journey.

Managed 99.3 mpg


99.3mpg by Rob E, on Flickr

Pretty pleased with this result. It's not reflective of "real world" usage which would involve cold starts, different air temps/weather, passengers, luggage etc but as an exercise and a bit of fun..?

[cRiPpLe_rOoStEr]

Originally Posted by rob.e

yes i've done some research but as this is my daily driver i don't have the luxury of taking this off the road to do any development work.. there don't seem to be any off-the-shelf kits for lpg into diesel and i don't want to do any damage experimenting.

There are some off-the-shelf dual-fuel setups, even though they're more frequently fitted to commercial vehicles.

This is an example I found on Google
https://www.lpgshop.co.uk/ac-stag-di...onversion-kit/

i'm sure there are gains to be made with lpg - from what i've read it works in a diesel a bit like nitrous in a petrol (gas) engine - ie makes more power.

It doesn't actually work in a way comparable to nitro. It may eventually make more power, but it only happens because the Diesel AFR is so lean that it allows enough oxygen to burn some extra amount of fuel to be accurately burnt. And since the volatility of LPG increases the flame spread, the Diesel fuel also has a more accurate combustion which by the way leads to a better usage of its energy content.

i don't want a faster car but maybe could be configured somehow to give my economy gains..

Using LPG to partially replace the Diesel fuel instead of supplement it is the way to go, and that's exactly the strategy followed by most operators who resort to it.

[euromodder]

Originally Posted by rob.e

yes i've done some research but as this is my daily driver i don't have the luxury of taking this off the road to do any development work.. there don't seem to be any off-the-shelf kits for lpg into diesel and i don't want to do any damage experimenting.

It works, with LPG or CNG, but in the EU you can't just toss in some gas gear .

I asked around years ago when I still had the V50 with 1.6L PSA diesel
It's possible
But not worth the cost & effort

On lorries you're talking about far more diesel use, thus far more to substitute with CNG/LPG than on a frugal diesel passenger car

[UFO]

Originally Posted by rob.e

Update:
I've booked for engine remap, should be mid-september i get this done.

The map runs the engine slightly leaner on part throttle (cruising) so i'm hoping to see a benefit.

Other positive of the map is it'll get me 309 ft lbs torque (418 Nm) if i need it, should make it pretty nippy i expect

I'm going to assume by "part throttle" you simply mean you are not accelerating, because diesel engines typically do not need throttles.

I also would not expect to get better mileage "leaning" the mixture at light loads because diesels always run lean; reducing the map at light load would simply reduce power forcing the driver to apply more fuel via the accelerator.