RSTuner - significant MPG decrease

[honkytonk]

So thought I'd buy an RSTuner, see what the fuss was about. TBH can't say I've noticed the kind of improvement some people talk of, I think its more of a placebo effect of thinking the car must be faster.

Anyhow, did the long drive to Huddersfield and noticed my MPG at the end was 31. I do this trip a lot, and its usually 40+ at a steady 80mph. Could really tell by the fuel gauge also - was almost on the light whereas I'd usually have around a fifth of a tank left. Anyone else found a similar effect? Reading on cliosport looks like people have seen it go up and down.

As a test, on the way back down I did 70mph for 30 mins and got 38MPG. 80mph for 30mins gave me 32MPG. I did this with and without cruise control (its a long drive!) and didnt have to change speed as travelled through the night. Tesco 99Ron. Will mail Henk see what he says - would be interested in others observations though.

 

[moono16v]

40+???? How?? Dont think I've ever seen 40. I don't have an RStuner or any other kind of mods and the best I can get is....about 36 and that's at 70-75.

 

[hoolio]

There is an equation, I think i've seen, that allows you to work out the optimum speed for best mpg for a particular car, a sweet spot where the extra power needed to go faster counteracts engine efficiency and starts to suck up fuel. For small cars that sweet spot is higher, but even being generous, mpg will decrease after 70. I think 40+ at 80mph is pretty unlikely, your 38 @ 70 and 32 @ 80 seem pretty good to me.

 

[ed55j]

I think i also average about 31mpg with the remap, slightly lower than original map, i never used to get above mid 30,s

 

[hodgy21]

On a 3 and a bit hour motorway journey mostly on cruise control at about 57-60 mph I managed 41.2mpg.

Unbelievably boring but economical.

Usual day to day trips to work and back, with a few quick drives here and there, I average about 32mpg.

I have no RS tuner map on it but I can't see the change being too drastic.

40mpg @ 80 sounds like its a fair way out BTW.

 

[scolbran766]

I can now do 45mpg on a 60mph 3 hour run after my remap at KTEC, was lucky to see 42mpg before.

Averages about 36mpg overall, even after giving it the beans.

 

[Carbon Chaos]

As an average mpg mine returns a 37-38 consistently over several thousand miles.

I think the manufacturers figure is 36 mpg on a combined cycle.

 

[MarcB]

As an average mpg mine returns a 37-38 consistently over several thousand miles.

I think the manufacturers figure is 36 mpg on a combined cycle.

Im around the same as above when driving sensible, When giving it stick it drops rather alot. I have the 98RON remap on my trophy.

 

[Robh18]

I can get 48MPG driving to Portsmouth from Hertfordshire at a constant 56mph

 

[hoolio]

I can get 48MPG driving to Portsmouth from Hertfordshire at a constant 56mph

OMG, why would anyone even do that? It's a 2ltr hot hatch, I rarely see much above low 30's and I don't think I've got too much wrong with my right foot. If I had been looking for 40+ I would not have bought a T and I'd be signing in to 'I'm a dull caravaner forum' not here.

Ahhhh happy now.

 

[moono16v]

OMG, why would anyone even do that? It's a 2ltr hot hatch, I rarely see much above low 30's and I don't think I've got too much wrong with my right foot. If I had been looking for 40+ I would not have bought a T and I'd be signing in to 'I'm a dull caravaner forum' not here.

Ahhhh happy now.

Haha what he said ^^^

 

[honkytonk]

I thought the mpg read out was lying to me also, 40mpg at 80mph seemed too high. So purely out of curiosity I geeked it up a bit and calculated the proper mpg from fill ups over a couple of months. Turns out the computer in mine over estimates by 1mpg and I average 37mpg with the standard map. On a long drive, I did indeed get 40+.

Henk from Fastchips reply was just some people see different results. Given I don't seem to get much benefit from the map I reckon I'll just switch back

 

[ed55j]

Its hard to drive economically in the trophy, now even more so with the yozza. Honkytonk it seems strange you havnt seen much of a benefit with the remap, oh well at least its only a 5 min job to change back to standard.

 

[Will#I#Ams]

best iv got out of mine so far is 28 lol...

 

[MarcB]

 

[Jonc]

I think in general remaps just runs the engine a little richer than normal. When I had the Unichip on the car, mpg was slightly lower, but there was slightly more mid range grunt and my exhaust tips were definitely more covered with soot. I just run it completely standard now and to be honest I don't feel I've lost anything in ditching the Unichip. I normally get around 32mpg on my short commute to the station and I have seen 44mg doing 60 on a long trip to the west country, 75mph equates to about 37mpg.