remapping for mpg?

[id101]

i'm in two minds what to do here.

on one hand i am told by the volvo specialist garage i use that remaps are a big no no and only destroy the engine whereas i see on here lots of happy people with remaps!

so my question that i'm sure has been asked before is are they in fact safe?

and if so what would be the best in terms of mpg?

i have a 53 reg s60 d5 100k on clock.

thanks in advance.

[bodger]

I can't really give you any definitive answers, but I've heard before that remaps are not always a good thing.

I would have thought only tuning for performance would cause premature engine wear however, although I guess if you run excessively lean you'll get valves burning out.

I've also heard that you're not going to get the best from a remap without changing other components eg air intake exhaust, which I guess makes sense for performance, not sure for economy though

I'd say you'd need to consider what kind of savings you're going to get compared to how much this will cost over the time you intend to keep the car

[princepugh]

My advice is don’t remap your car expecting an improvement in MPG – if you do, it’s a bonus!

An off the shelf remap will give you a noticeable improvement in mid-range and high-end performance. How you use the car after it has been mapped will determine any increase in engine wear rate – if you’re running around at full throttle hitting the redline regularly then you might expect to see a reduction in the lifetime of the engine and/or components as well as MPG.

My experience is that the remap means you don’t have to rev the engine as much to get the car up to speed, or to make an overtake so I’m personally spending less time near the redline and less time at WOT.

The MPG improvement is subject to much debate – think about what the remap is changing – mainly boost, ignition and fuelling. For a petrol engine, the map may be biased towards high RON fuel so if you’re not constantly pushing the pedal through the bulk-head you may see an improvement in MPG due to less knock and better ignition timing but I think even this is marginal. On the flip-side, most remaps go into fuel enrichment under heavy load so you fuel richer than lambda, protecting against knock and engine wear but using more fuel…..

In terms of changing the air intake and exhaust etc. – yes, bigger gains in power but more risk of wear and destruction and you’re probably into custom mapping territory, which would defo not be mpg orientated. Not sure many folk would go that far with a D5 though.

D5 specific, other than a Stage 0 tune-up you’ve got the intercooler and DMF to consider and possibly the health of auto transmission.

Plenty of information on here and T5D5 if you’ve got time to search and plough through the results.

BTW – I remapped my T5 at something over 92k and its still going strong at nearly 170k.

HTH

[grainqey]

if you get a half decent map then they're not bad at all, after that its all how the driver treats it, really its like any unmapped car but with more potential wear (unless its a ****e map) lol
personally in my D5 i saw an increase in mpg...when i wasnt getting the extra power out of it :P
HTH
alex

[adamr8965]

You can gain more mpg without remapping the car.
You can lift off the throttle early when slowing down, Accelerate gentle and keep the revs low.
Block changing of the gears.
Correct tyres pressures, Clean oil in the engine, Sit at 50mph rather than 60mph.

Do all those and you'll be suprised how much your mpg will improve by, plus you have saved yourself around £450 for a decent remap.

[Brendan W]

I don't get the remap thing at all. Imagine Volvo chewed a fair few pencils optimising their machines.

[grainqey]

Originally Posted by Brendan W

I don't get the remap thing at all. Imagine Volvo chewed a fair few pencils optimising their machines.

theyre tuned to run on any old specification of fuel
america have 91/93 ron IIRC uk is 95+

[Jim314]

Originally Posted by grainqey

theyre tuned to run on any old specification of fuel
america have 91/93 ron IIRC uk is 95+

In my area the offerings are ron 91, 93, and 97. When I fuel I usually mix approx equal amounts of 93 and 97 to produce 95.

My V70 owner's manual states that the minimum allowed is ron 91, but Volvo engines are tuned to achieve optimal performance on ron 95 or greater.

I gather that there is a knock sensor which retards ignition timing if knocking is detected, and one assumes that this would only occur with agressive driving with sub 95 fuel. The explanation that a remap would improve mpg must assume that the remap changes the ignition timing program to favor running on 95 or 97 ron petrol at the expense of performance on sub 95 fuel, but nobody ever gives any evidence for this.

I'm very skeptical that any remap would improve mpg. The idea that a remap could improve mpg seems to me a false argument designed to justify the expense of a remap whose real pupose is to increase max power.

[fierceteapot]

Originally Posted by bodger

I can't really give you any definitive answers, but I've heard before that remaps are not always a good thing.

I would have thought only tuning for performance would cause premature engine wear however, although I guess if you run excessively lean you'll get valves burning out.

Don't diesels just slam home whatever fuel they need? Surely running lean would just mean less revs?

[grainqey]

Originally Posted by Jim314

In my area the offerings are ron 91, 93, and 97. When I fuel I usually mix approx equal amounts of 93 and 97 to produce 95.

My V70 owner's manual states that the minimum allowed is ron 91, but Volvo engines are tuned to achieve optimal performance on ron 95 or greater.

I gather that there is a knock sensor which retards ignition timing if knocking is detected, and one assumes that this would only occur with agressive driving with sub 95 fuel. The explanation that a remap would improve mpg must assume that the remap changes the ignition timing program to favor running on 95 or 97 ron petrol at the expense of performance on sub 95 fuel, but nobody ever gives any evidence for this.

I'm very skeptical that any remap would improve mpg. The idea that a remap could improve mpg seems to me a false argument designed to justify the expense of a remap whose real pupose is to increase max power.

its quite easy to justify, at 10% throttle you will have a greater amount of power/torque, then before mapping so require less throttle and you'll inject a more exacting amount of fuel as it will be optamised