- Car engine re-map, worth it at a rate of £1.50 per hp?
I have a car with a fairly basic petrol engine. A quick look on the internet suggests I can achieve an additional 10hp for £150 (this was a pre-xmas offer). I know its not going to set the world on fire, however the car isn’t doing amazing MPG and I’m sure the 10% power increase will make a bit of a difference too.
The car is due a fair bit of work in a few months (service, cam belt) so thought about trying to get this added to the deal and get it a bit cheaper. This car is going to be a keeper as apart from the poor fuel economy its in good condition and should be good for another 5 years and we owe no money on it.
I am aware that they can achieve different things with the re-map but is there a rule of thumb that would make it worthwhile, ie <£1 per ho / 1 mpg increase? I’m hoping that a good person can achieve extra power and mpg for about £200.
If anyone can recommend any good mobile or Sheffield based people that can do this please let me know.Posted 5 years agorichmtbSubscriber
If its a Normally Aspirated petrol engine then there is a limit to what can be achieved with a simple remap.
Whether 10HP is worth the price really depends on how much power you have at the moment. if you have 90hp then 10 is a fairly useful increase. If you have 200hp then I doubt you would even feel the differencePosted 5 years agobigyinnMember
Firstly what car is it? 10bhp is nothing to write home about and will probably not make much difference, but if its only putting out 40bhp then you might.Posted 5 years ago
The increase in bhp may decrease the fuel economy, as you dont get something for nothing!
Is the car still in warranty, as remapping will almost certainly invalidate this.
Also bear in mind that you’ll need to declare the remap to your insurance. Failure to do so may invalidate it.
tbh a good deep service would achieve the same increase.
remap gains are for cars with turbos bolted on. N/A petrol engines are not going to see any great increases.
youll probably find that itll move the max BHP up the curve and the torque will fall – id take torque over BHP anyday of the week.Posted 5 years agohoraMember
If It was a Aygo yes for a Leon though- its not enough IMO for £150. for that much money I’d want 30bhp to make/feel a difference (weight of car).
10hp when the current power is 65hp in a 800kg car would make a noticeable difference if that makes sense.
You’d be better off with a fresh (self) oil service/filter and aftermarket air filter.Posted 5 years agojoao3v16Member
A remap also won’t necessarily give you better mpg. I once queried a remap of a n/a petrol car with a few specialists. For the engine in question they said the fuelling would not be changed. The best I’d get was increased torque, but the increase was probably too small to be noticeable.
Most remap specialists seem to go on about “improved driveability” … whatever that actually means in the real world …
I suspect a good service and oil change will be as good as anything for a non-turbo engine.Posted 5 years agotoppers3933Member
I’ve been toying with getting my octavia vrs remapped. It will add 35bhp and about 80ft/lb of torque. which is probably worth doing. all for £200.Posted 5 years ago
10hp is not worth doing. As said a good service done by yourself to keep the cost down and leave it at that. Also make sure your brakes are in good order. If they are seized up and binding that will ruin your mpg.andytherocketeerSubscriber
I wouldn’t pay that. Didn’t even bother remapping my 1.8t, although I could have got something out of it. Really need to start swapping parts to get anything useful (CAI, turbo, etc.), or reliable (DV, coilpacks, etc.), with half of those changes not applicable to a NA car. Think I could have gone from 180PS to about 210PS (claimed), but in reality, the car has probably lost more horses just due to age.Posted 5 years ago
anyone remember the old topgear with the massive peoplecarrier … the big renault
was supposed to have 220bhp or something and was pulling about 150 on the dyno. they got the most gains(on the dyno and the track) out of anything they did by giving it a full service – other things they did was light alloy wheels , better tires , suspension and brakes…. but the service made the most gains.Posted 5 years ago
I bought 7 SMART ForTwos for my Business a few years back and I put a stage 1 on 5 of them and left 2 alone (basically I couldn’t get them all done at once,time/distance etc.) anyhoo’s of those that were done (and only I knew which ones) the Kids that used to drive them could tell and would always plum for the “modified” ones. I took some readings on petrol use (around London) and came to the conclusion that on SMART ForTwo’s it’s worth doing. (I eventually got the remaining 2 done as well)Posted 5 years ago
I kept one of the SMARTs for myself and enjoyed it, it just felt a lot easier and spritly to drive, sold it on to a mate and he’s happy with it.
I’d never go over stage 1 on a SMART though, even though it’s been proven it works well.
I did put a performance chip on one of my old BMW530D Sport Tourings and that was immense.. 😉parkesieMember
If its due a major service youl most likely see the improvement you seek just from the service. Especially if youve noticed the mpg dropping.Posted 5 years ago
£150 on ecu remap is at best a generic map at worst a bottle of snake oil and a sticker in the form of a resistor on the temp sensor.
Especialy on a n/a motor a proper remap is done with use of rolling road before and after with money thrown at making improvements to the engines breathing aswell. Even then 10bhp is a good gain on some motors.
SMART ForTwo’s are indeed turbo’d.. it’s very common to get them remapped, there is a whole industry built on the back of a strangled 500 or 600 or indeed a 700cc engine trying to pull along two fatties. You could (don’t know now) get a remap done at a SMART dealer at one point..Posted 5 years ago
I think mine cost £100.00 inc Vat at the time, I just about saved that on fuel over a year but it was the drivability that made them nicer, it also helped with the auto gear change which is notoriously poor on them.
I know someone who has a stage 4 mapped (and modded) Brabus ForTwo and it’s quite bonkers, thankfully he’s uprated the brakes and tyres to cope. I almost bought a Brabus myself, but I was deluded.DaveyBoyWonderMember
Am I missing something? How will increasing the power by 10bhp lower the MPG?
If you read what tuners say then their logic to this is that the car will reach speeds quicker so less acceleration time = better fuel economy. Real world though, even on my Octy vRS I’d only be looking at 2 or 3 mpg more than I’m getting now, at the very most. I doubt I’d notice it.
Certainly wouldn’t be mapping mine for better economy…Posted 5 years ago
their logic to this is that the car will reach speeds quicker so less acceleration time
How does that work? Quicker acceleration = more fuel for a shorter time = the same as less fuel for longer.
However more torque at lower revs might improve fuel economy, depending on the engine I suppose and how the original map is set up.
I think the only sensible way to increase efficiency by a remap is to change ignition timing, isn’t it? This could increase emissions though and also give you less margin for using poorer fuel.Posted 5 years agotimberMember
Improving engine efficiency through air flow, ignition and lubrication – otherwise it’s like going for a ride with a cold, whilst hungry, on a rusty bike. Car will feel more responsive with a feel of progress and better economy. This would be the better route for the OP.
Mapping works more noticeably on turbo engines, otherwise it’s just playing with air/fuel mix. A lot of manufacturers tend to assume a lower fuel quality than we have in the UK, this is where gains can be made too. Worth knowing a mapper that knows when to stop, the engine may be good for 250, but that is pointless if the gearbox won’t take more than 200.Posted 5 years agoThrustyjustMember
My Focus ST has the Mountune upgrades done. All under the Ford banner, all TuV approved, no difference to insurance costs, keeps the warranty ( although now expired). It doesnt make any difference to fuel consumption and the difference is huge. I dont think it would be authorised from Ford if it didnt make emmisions to guidelines from the EU. With other mods on top I should be about 290 bhp, which is fine for a small hatchback car. Its a bit more than the 223bhp from new.Posted 5 years agopjm84Member
I had my TD5 Defender 90 remapped. It upped the horsepower to 150hp ish from 122hp but made it so much more driveable. Fuel wise it was around the same. 26 to 30mpg. So no improvement!
Air filter…. I had an bad experience with one of these. The oiled filter deposited the oil (from the filter – strange that!) onto the MAF sensor over a period of time. Luckily I figured it out quite quickly, cleaned the MAF sensor and put the OEM filter back in.Posted 5 years ago
“I had my TD5 Defender 90 remapped. It upped the horsepower to 150hp ish from 122hp but made it so much more driveable. Fuel wise it was around the same. 26 to 30mpg. So no improvement! “
that map removes the huge dead spot the 5 pots prone to though.
you can do some amazing things with those engines for what they are. far better than thePosted 5 years ago
pumatransit engine thats replaced it.coffeekingMember
I could write you a short book on this subject (a real interest of mine,I’ve mapped a few engines including my own from scratch) but I will simply say for a 1.6 petrol n/a you won’t notice a difference in power or economy worth that price. save your cash. there is plenty that can be achieved but it is almost impossible for an end user to discern the difference in economy or power without falling foul of complicating factors like the placebo effect.
And just to be pedantic, a service won’t give you any gains, it just cuts a few losses.
You can marginally improve some modern engines breathing and efficiency, but not while keeping legal items like cats, or original filtration. Some cars are crippled purposefully, but returning them to their full capacity won’t be easy or cheap generally if they are n/a. plenty of folk will tell you their mods help airflow etc but very few IME have fluid dynamics knowledge and understanding of the resonant tuning used by OEMs.Posted 5 years ago
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