Colin Heseltine Posted April 19, 2021 Share Posted April 19, 2021 What sort of fuel consumption figures are you guys getting with 420R. I have new 420R and have followed running in recommendation of 500 miles at max of 4000rpm and am increasing by 1000rpm every 150 miles. Now up to 850miles. My average appears to be around 28-29mpg. During the first 500 miles the average was around 30mpg, a bit lower than I would have expected as I was not being stupid as trying to get used to the increase in power over my previous 158bhp 'K' supersport.Colin Link to comment Share on other sites More sharing options...
John Vine Posted April 19, 2021 Share Posted April 19, 2021 I'd say that was fairly normal. Looking at my records, my R400D (with plenum at the time) averaged 27.9 over the first 1100 miles, with a gradual improvement as everything loosened up.. Since my roller-barrel upgrade in 2014, I've been getting 28-33, depending on conditions, with the higher figure achieved on quiet and traffic-free French D-roads.JV Link to comment Share on other sites More sharing options...
Blackmamba Posted April 19, 2021 Share Posted April 19, 2021 30 mpg strikes me as pretty good for a car in a relatively high state of tune.Hi Colin - What did you get from your K series out of curiosity?Thanks Link to comment Share on other sites More sharing options...
7 wonders of the world Posted April 19, 2021 Share Posted April 19, 2021 My Duratec normally offers circa 25mpg................and on a good day 9mpg Link to comment Share on other sites More sharing options...
ScottR400D Posted April 19, 2021 Share Posted April 19, 2021 I have absolutely no idea what I get! 6 years since I built the car I'm yet to check....... Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted April 19, 2021 Area Representative Share Posted April 19, 2021 With RBTB & 'careful' driving one may see 220 miles out of an S3 tank. On track or nailing the car on the road to the legal limit (honestly constable) may only see 180 miles or less from a tank.Touring ser le continent with the speed limiter in the pax seat will easily see 30 mpg.Fuel quantity anxiety/management is all part of the 400/420 experience. Is mpg that important when driving a road weapon like a 400/420 ? Just enjoy. Link to comment Share on other sites More sharing options...
Colin Heseltine Posted April 19, 2021 Author Share Posted April 19, 2021 Don't get me wrong, I am enjoying the car and the extra performance. My previous 1600 K series would give me typically 38mpg, sometimes as low as 35mpg, other time low 40's.Geoff, I like your 'Fuel quantity anxiety/management is all part of the 400/420 experience'.I think a bit of the problem is the wild swings the gauge makes, up hill and downhill can swing the needle over 1/4 of the gauge,so need a level road and steady driving to get a an accurate reading.Thanks for all your responses.Colin Link to comment Share on other sites More sharing options...
7Up Posted April 19, 2021 Share Posted April 19, 2021 I would say that is brilliant for a 420R. I have got 18 MPG since new, 5500 miles. Link to comment Share on other sites More sharing options...
John Vine Posted April 19, 2021 Share Posted April 19, 2021 ...18 MPG...Does that include trackdays?JV Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted April 19, 2021 Share Posted April 19, 2021 10 litres / 100km (28mpg) around town and in touring type use, 20 litres / 100km (14mpg) for track day use with my R400D. The track day fuel consumption is actually much better than other cars I've used on the track due to the light weight, I used to get 50 litres / 100km (6mpg) from my BMW Z4M. Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted April 20, 2021 Area Representative Share Posted April 20, 2021 400/420 fuel anxiety/management does include the fuel gauge. An approximate instrument system if there ever was. My gauge when showing half the tank physically has nearly one quarter more (2 gallons). When showing one quarter physically has again nearly one quarter more.Eventually I worked this out by being suicidal - on returning from Quay 4 my car a few years ago I thought that I had sufficient fuel to return home (Poole - Swindon). Just after entering the Salisbury plain area SWMBO mentioned the fuel gauge was nearly on zero. With 25 miles to run & foot off the gas a tad she calmly stated that the needle was resting on zero Safely arrived home & next morning topped up tank. The splashing of fuel on bare aluminium told a story! So from there I calibrated fuel state against the gauge.Now I know that with the gauge needle on zero I have 22 - 25 miles of fuel remaining. My constant mantra is fill up when indicating just below one quarter even though there is more in the tank. Link to comment Share on other sites More sharing options...
7Up Posted April 20, 2021 Share Posted April 20, 2021 Yes correct - but does not seem to change much when only on the road! Link to comment Share on other sites More sharing options...
Alan Reeves Posted April 20, 2021 Share Posted April 20, 2021 wel7 Up i reckon thats a tad wrong for road use. i would say my 210 certainly does 30mpg road use onlybut reasonably quick blatting in Euro mountains etc Link to comment Share on other sites More sharing options...
Benton Posted April 20, 2021 Share Posted April 20, 2021 but does not seem to change much when only on the road!if you don't drive like the Stig all the time on the road, if you haven't done already I'd take a look at the plugs to see if Sooty has taken up residence due to an underlying over fuelling problem. Link to comment Share on other sites More sharing options...
John Vine Posted April 20, 2021 Share Posted April 20, 2021 Re #12 and #14:I'd say something was wrong there, too. How are you measuring miles travelled? Satnav, map, odometer?JV Link to comment Share on other sites More sharing options...
Colin Heseltine Posted May 16, 2021 Author Share Posted May 16, 2021 After a two day Blat (Friday/Sat) with 6 others round the Scottish Borders with overnight in Dumfries I covered 675 miles. I averaged 30.5mpg overall, with a low of 26.6mpg and a high of 34.5mpg (return trip down M6 J40 to J15 in howling storm).My fuel gauge also now appears to behave itself. I'm wondering if the bush the float arm runs in has been sticking and has now freed off. As Geoff says above i think when down on the 1/4 mark there is at least a gallon more than one would be led to believe.Overall a lot happier with the consumption.Had a couple of minor issues with car. Indicator switch just puts indicators on and does a continous beep. The lock on the fuel filler cap gives me no confidence I will be able to either lock or unlock it. 12volt socket also appeared to fail. Few more jobs to add to the warranty list.Colin Link to comment Share on other sites More sharing options...
Toby S Posted May 16, 2021 Share Posted May 16, 2021 Blimey 38mpg out of 1600 k series - My 1400 Supersport is nowhere near that - 200-220miles out of tank and that's about it (and that's with areoscreens so less wind resistance) - mind you I don't hold back on revving the arse off it (engine sweet spot is 5,300-7,500) and rarely use dual carriageways/motorways and therefore 5th is rarely used Link to comment Share on other sites More sharing options...
SM25T Posted May 17, 2021 Share Posted May 17, 2021 That is probably 33-34mpg Link to comment Share on other sites More sharing options...
Toby S Posted May 17, 2021 Share Posted May 17, 2021 Maybe - 220 miles is getting seriously squeaky bum time - generally I refuel at around 200 mile mark and around 30 litres, bit under so I reckon 30/31ish - still better than when I had a Mk2 RX7 - 185 miles out a tank if you really went for it - circa 16/17 mpg - even general drving around 23/24m.pg was typical - mind you those were the days when you could fill up a big tank for under £40 - in the days when you mainly had red nozzles on the forecourt Link to comment Share on other sites More sharing options...
Roy Blyth Posted May 18, 2021 Share Posted May 18, 2021 Fuel consumption...? In a Seven...? Are you all mad?! #4 and #5 - I'm with you Link to comment Share on other sites More sharing options...
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