Custom Tuning the Gren - for power? For Mileage?

[ChasingOurTrunks]

HI folks,

Lots of excitement about the Grenadier coming out of course, and one of the topics that comes up a lot is the range of the petrol version and the overall fuel economy of the V6. I think the V6 [EDIT - the 6 cylinder; I mis-typed this one as Dave has pointed out it's an inline 6 not a V6!] is a fantastic engine choice - I have a V6 putting out similar HP and torque numbers in my truck, and the performance is fantastic. However, candidly, the fuel economy could be way better; when my rig was empty, I was getting fairly good mileage but with it loaded and built out, I only get about 450 kilometers of range -- less than half what I'd like. And, I'm fairly heavy already so bringing extra fuel in jerrys or an auxillary tank isn't ideal; I'd need to cart an extra 200lbs of fuel around (plus tank weight) to get to 1000kms.

This past summer, I was able to consistently get 11 liters/100 kilometers, and it jumped my range up to over 600 kms. However, to achieve that, I had to "force" my rig to shift into 8th gear on the highway at 80-100 KPH; otherwise it didn't seem to want to up-shift to reduce my RPMs at typically highway speeds. But, it almost seems that the shift-points are based on an empty rig, so they aren't quite in the right spot for a heavy rig, if that makes sense.

On the Gren, I believe the BMW will be substantially de-tuned and understressed compared to what it's capable of, and I've read of folks getting some good performance and power upgrades from the B58. And what experience do folks have on custom tuning for fuel economy? I know folks get custom tunes all the time for more power/torque, but was wondering if anyone had any knowledge of doing this for range/fuel economy, and who plans to get a dyno tuning done on the Grenadier?

 

[DaveB]

HI folks,

Lots of excitement about the Grenadier coming out of course, and one of the topics that comes up a lot is the range of the petrol version and the overall fuel economy of the V6. I think the V6 is a fantastic engine choice - I have a V6 putting out similar HP and torque numbers in my truck, and the performance is fantastic. However, candidly, the fuel economy could be way better; when my rig was empty, I was getting fairly good mileage but with it loaded and built out, I only get about 450 kilometers of range -- less than half what I'd like. And, I'm fairly heavy already so bringing extra fuel in jerrys or an auxillary tank isn't ideal; I'd need to cart an extra 200lbs of fuel around (plus tank weight) to get to 1000kms.

This past summer, I was able to consistently get 11 liters/100 kilometers, and it jumped my range up to over 600 kms. However, to achieve that, I had to "force" my rig to shift into 8th gear on the highway at 80-100 KPH; otherwise it didn't seem to want to up-shift to reduce my RPMs at typically highway speeds. But, it almost seems that the shift-points are based on an empty rig, so they aren't quite in the right spot for a heavy rig, if that makes sense.

On the Gren, I believe the BMW will be substantially de-tuned and understressed compared to what it's capable of, and I've read of folks getting some good performance and power upgrades from the B58. And what experience do folks have on custom tuning for fuel economy? I know folks get custom tunes all the time for more power/torque, but was wondering if anyone had any knowledge of doing this for range/fuel economy, and who plans to get a dyno tuning done on the Grenadier?

It is an inline 6 (i6) not a V6

 

[ChasingOurTrunks]

It is an inline 6 (i6) not a V6

Bah, that'll teach me. I should have drank more coffee before posting. Thanks Dave, edited the initial post to catch it.

 

[AnD3rew]

Personally I doubt there are significant gains to be had in economy from tuning, I think economy is going to be mostly about weight and driving style. It’s already a heavy vehicle shaped like a brick, INEOS has already tuned to bring the power down and the torque down lower and wider across the rev range which should be decent for fuel economy. Trying to get more economy from it is going to be tough I think and would involve some serious compromise.

 

[caalm]

HI folks,

Lots of excitement about the Grenadier coming out of course, and one of the topics that comes up a lot is the range of the petrol version and the overall fuel economy of the V6. I think the V6 [EDIT - the 6 cylinder; I mis-typed this one as Dave has pointed out it's an inline 6 not a V6!] is a fantastic engine choice - I have a V6 putting out similar HP and torque numbers in my truck, and the performance is fantastic. However, candidly, the fuel economy could be way better; when my rig was empty, I was getting fairly good mileage but with it loaded and built out, I only get about 450 kilometers of range -- less than half what I'd like. And, I'm fairly heavy already so bringing extra fuel in jerrys or an auxillary tank isn't ideal; I'd need to cart an extra 200lbs of fuel around (plus tank weight) to get to 1000kms.

This past summer, I was able to consistently get 11 liters/100 kilometers, and it jumped my range up to over 600 kms. However, to achieve that, I had to "force" my rig to shift into 8th gear on the highway at 80-100 KPH; otherwise it didn't seem to want to up-shift to reduce my RPMs at typically highway speeds. But, it almost seems that the shift-points are based on an empty rig, so they aren't quite in the right spot for a heavy rig, if that makes sense.

On the Gren, I believe the BMW will be substantially de-tuned and understressed compared to what it's capable of, and I've read of folks getting some good performance and power upgrades from the B58. And what experience do folks have on custom tuning for fuel economy? I know folks get custom tunes all the time for more power/torque, but was wondering if anyone had any knowledge of doing this for range/fuel economy, and who plans to get a dyno tuning done on the Grenadier?

You can detune for better economy, but it tends to ruin the driving experience


I've booked mine in for more noise

 

[Tom D]

I had a TDCI defender re-mapped and it was actually slightly better on fuel, wasn’t a massive difference, but the extra power was nice! The Gren has way more power than the defender though so I don’t think I’d do it this time.

 

[DaveB]

Personally I doubt there are significant gains to be had in economy from tuning, I think economy is going to be mostly about weight and driving style. It’s already a heavy vehicle shaped like a brick, INEOS has already tuned to bring the power down and the torque down lower and wider across the rev range which should be decent for fuel economy. Trying to get more economy from it is going to be tough I think and would involve some serious compromise.

Agree. Load it up as you normally would and then put half the crap back in the garage
I can't believe some of the stuff I see people loading there vehicles up with for holidays

 

[Shaky]

Agree. Load it up as you normally would and then put half the crap back in the garage
I can't believe some of the stuff I see people loading there vehicles up with for holidays

Agreed, put the kids, Mrs and dogs back in the house and the MPG will increase significantly for your holidays.

I have also ordered the petrol and thought about exploring an economy tune, which I still might do if a very good one comes out.

However, I put it to the back of my mind as in my case it won’t be my daily driver, and I won’t be doing that many miles a year in it.

My thought process is this, in the UK petrol is currently 20p a litre cheaper than diesel (approx) which will make quite a bit of difference in equalising things and with such low mileage any economy tune will take quite a while to retrieve the initial cost of the tune before I even see any savings.

My conclusion was, leave well alone for the time being.

If someone wants a performance tune then I am sure there will be a mass that will be available that will give instant results. The cost of those is irrelevant in some ways, otherwise you wouldn’t be after more power if that was a concern.

 

[ChasingOurTrunks]

Great info so far folks, thanks all!

I did some googling and found this informative article from Motortrend; https://www.motortrend.com/how-to/0510ht-fuel-economy-tuning/

A couple of the things that jump out to me from that article:

1) Engine tuning for them resulted in 2% gains. I've read elsewhere that some big diesels will see as much as 20% gains, but that seems far more rare than the 2%-ish number reported by motortrend. On my current rig - similar numbers to the Grenadier in terms of torque, HP, and weight -- 2% fuel economy savings would result in an increased range of about....10 extra kilometers of range per full tank of gas. That's hardly worth it.

2) The easiest way to gain effective range is to change the way you drive; the article suggests 10%-20% increased fuel economy, which means 50 to 100 extra kilometers range per tank. That's getting into real gains.

3) The article made a statement to "Shift as early as practical while accellerating (between 2500 and 3000 RPM for most vehicles)" and "Use the highest gear possible", and I think this is where there might be some tuning gains to be made, but I wanted to check this assumption with the folks on here with more wrinkles on the brain than I have. The Grenadier will have an 8-speed auto, similar to the one in my truck currently. My truck has a mode that allows me to "manually" lock in a specific gear (the Gren will have this too). What I've found is that when I'm accellerating, my truck will often get up to the 4k-5k RPM before shifting. When left in "D" (drive), it will also often stick into, say, 6th gear at 3400 RPM, when I could put it into "L" (lock) and manually tell it to shift into 7th gear on that same road for only 2800 RPM with no major performance changes, which is significant fuel savings. The rig is a little less "punchy" when I do this on acceleration, but its still very good and tolerable. Of note - on the highways, I actually get better fuel economy at 125 kph than I do at 110 KPH; at 110 KPH my truck "sits" in 7th gear at a relatively high RPM and doesn't up-shift; at 125 kph it shifts into 8th gear and the RPM to maintain that speed drop a good bit (there are other factors of course - wind, grade, etc. -- but the weight of my rig is fairly consistent).

Has anyone got experience with reprogramming shift points on a vehicle in terms of seeing range increases? And how does the weight of the vehicle intersect with transmission shifting? I've been thinking a lot about this and candidly I'm just not sure if a 4500 lbs Gren would benefit from different shift points than a 6500 lbs gren or not.

I'll keep thinking on it till one of you wise folks tells me the answer, or I have a bump on the head that allows my three brain cells to collide in just the right way to figure this out -- whichever comes first!

 

[globalgregors]

HI folks,

Lots of excitement about the Grenadier coming out of course, and one of the topics that comes up a lot is the range of the petrol version and the overall fuel economy of the V6. I think the V6 [EDIT - the 6 cylinder; I mis-typed this one as Dave has pointed out it's an inline 6 not a V6!] is a fantastic engine choice - I have a V6 putting out similar HP and torque numbers in my truck, and the performance is fantastic. However, candidly, the fuel economy could be way better; when my rig was empty, I was getting fairly good mileage but with it loaded and built out, I only get about 450 kilometers of range -- less than half what I'd like. And, I'm fairly heavy already so bringing extra fuel in jerrys or an auxillary tank isn't ideal; I'd need to cart an extra 200lbs of fuel around (plus tank weight) to get to 1000kms.

This past summer, I was able to consistently get 11 liters/100 kilometers, and it jumped my range up to over 600 kms. However, to achieve that, I had to "force" my rig to shift into 8th gear on the highway at 80-100 KPH; otherwise it didn't seem to want to up-shift to reduce my RPMs at typically highway speeds. But, it almost seems that the shift-points are based on an empty rig, so they aren't quite in the right spot for a heavy rig, if that makes sense.

On the Gren, I believe the BMW will be substantially de-tuned and understressed compared to what it's capable of, and I've read of folks getting some good performance and power upgrades from the B58. And what experience do folks have on custom tuning for fuel economy? I know folks get custom tunes all the time for more power/torque, but was wondering if anyone had any knowledge of doing this for range/fuel economy, and who plans to get a dyno tuning done on the Grenadier?

Retuning for economy often relies on leaning out the charge, which typically will erode performance under load (eg towing, mud/sand) and at altitude (unless the tune appropriately compensates for oxygenation, or lack thereof).

Could be the ECU in the Grenadier is more sophisticated than the one we have in the (2015) DS, but despite efforts we were unable to produce a tune which accommodated for altitude and therefore went in the opposite direction, essentially tuning for additional (mid range) power.
The impact of this however was disproportionate to the loss of economy... perhaps due to us operating the DS near GVM while the factory tune perhaps being prepared at wet weight. Actual engineers please correct me if my layman's understanding is off.

With the DS, my understanding is that the core issue was the pursuit of EURO 5 compliance on an engine architecture designed for an earlier compliance gen - our early DS has the SD4 (eg from the Freelander) rather than the Ingenium that the driveline was designed for (which was held up for the first year of DS model production). My point being that the interaction of the emissions system and the degree to which the engine architecture and emissions system are co-designed can be the source of your limits, rather than the performance elements attributable in the ECU.

Adjusting shift points was an element of the remap, and (again, speaking for the DS) is actually done multiple times as that power plant offers 'standard' and 'economy' modes, which are essentially alternative/toggled maps.

 

[DCPU]

I had a TDCI defender re-mapped and it was actually slightly better on fuel, wasn’t a massive difference, but the extra power was nice! The Gren has way more power than the defender though so I don’t think I’d do it this time.

Who did you use for that?

 

[Tom D]

Who did you use for that?

These guys I think..https://bellautoservices.co.uk/store/defender-engine-remaps/

 

[Too many trucks]

I had a TDCI defender re-mapped and it was actually slightly better on fuel, wasn’t a massive difference, but the extra power was nice! The Gren has way more power than the defender though so I don’t think I’d do it this time.

Did the same with mine, Bell auto retune, larger intercooler, and the cat fell out the exhaust (JLR quality, typical!) Anyway, went from 24 mpg to a solid 28 mpg, this is on a 2.4 tdci 110 station wagon. Its down to about 12mpg now as I ripped out the dirty diesel and fitted a nice clean petrol 6.2l LS3 V8, 'tis damn quick and utterly pointless, work on smiles per gallon now.

 

[DCPU]

These guys I think..https://bellautoservices.co.uk/store/defender-engine-remaps/

A very solid reputation in the Defender world. I believe he's got a Grenadier on order and will be looking to do a few things with it in the near future.