10.6 afr at idle is pretty unlikely for a road car, and yes when decelerating between certain rpm regions with zero throttle there is no fuel being injected. Although if you are asking about a comparison of coasting down hills in neutral or just backing off the throttle. The factor of how steep the hill is and the speed you don't mind dropping too come into the equation.
What is the optimum rpm for gear changes?are they different for every gear or a standard across all?also how much affect does changing too early have so engine judders a bit and struggles until in better rev range?does this also burn more fuel. On another note I don't have a rev counter in my crappy fiesta but I do always pop it out of gear and coast down hills.
Also remember that a full tank of fuel = more weight. My digi is quite bad on fuel compaired to others. If I floor it I do notice the fuel needle go down.
Read this yesterday and thought Id give it ago. I managed 34mpg over 26 miles (20 clear mway and 6 town). This morning only managed 22 doing the school run. I do have a fluctuating rev problem so I dont think my car is in the best state of tune so Im sure there are improvements to be had.
The other posibility I consderd, a 1.6 FSI conversion. The engine on paper has similar chracteristics in terms of pwoer and torque as the original 8V, yet in the lardwagen its bolted to returns mid 40s, possibly 50 MPG IIRC. So when nearly half the weight has been removed by replaceing the car with a Mk2 what would it return then? this should be with little or no loss in perfomance. At the moemnt the doner car is too expensive but I feel this may be a worthwhile convresion in the future
In a Golf MK5 (lardwagen), such an engine also works with battery regen, optimised gearing, Vehicle uppper and lower body aero enhancements, low friction tyres. Very similar to the 2010 1.6 Focus with the expection of the direct injection NASP engine.
With regards to aero, doesn't the Mk5 have the same drag CD as a Mk2? I'm sure I read the figures being the same on here once before.
Interesting, so how does the FSI differ from a normal stratified charge engine? Instereted to know how the battery regen (Which I thought was a brakes thing on hybryd types) works! If I get round to doing such a conversion (should the engine/car become cheap enough). Stratified chagre engines did when first tested in the 70's show fuel efficiency comprative to the diesel engines of the time, while not suffreing the lack of perfomance and excessive noise associated with dervs however the cost of the electronics at that time and the fact that derv was much cheaper than petrol meant it was shelved, however recently the fuel price situation has been reversed.. and electronics have become far far cheaper
good write up..my wifes old 170k miler 8v used to get 40 regularly.. i put it down to the fact that it weighed nowt compared to modern hatches and i stuck a 4+E 'box in it
Great scientific test Eddy. I am looking forward to warmer weather. I remember doing ~36mpg over the summer, but now I am struggling to hit 32mpg even when following the trucks home at 60mph. As you say, there is a much longer warm up time in colder weather and also more use of window demister and other power hungry equipment. Is there any easy way to quantify how much extra fuel is used in warm up mode? Before BTS is up to temp and signals to ECU? Jon.
Fuel economy spot check. 51.7mpg achieved in a 61 mile trip. Who needs a diesel! With petrol prices continuing to rise, I have been using JORAN as the daily commute vehicle. Generally, sensible but not fuel economy focused driving, results in and average 40mpg. Ever since achieving a reported 50.5 mpg for a trip in the past exercise, I have always been intrigued if better could be done. Today it would seem that question can be answered. After 61 miles, and 1 hr 12 mins, my final MPG was: During this drive the MFA, which in the original exercise was proven to read 'well' on this vehicle, displayed as high as 52.3mpg but my driving style was interrupted by another road user on the motorway, who pulled out in front of me, meaning I had to brake then put more throttle in to maintain vehicle speed thus increasing engine fuel flow. Vehicle was started from 'cold' i.e. air and coolant of ~ 7C but I had to back up before setting off, which added some penalty to the overall result. During the warm-up period, and in hindsight, B-A-B road driving with speed limits at 30 and 40mph respectively, I could have been more eco focused in my driving. These improvements could have seen the final result at 53ish mpg. NB Vehicle is in the same condition as the last test .
After 2000k miles since I got it from you it is indeed still in top form, achieving Diesel like fuel economy. You look after it very well
According the vehicle full service history and state I received it rom the past owner (logans run) well looked after but not in a performance specific way.
JORAN 439 miles from a tank. A few weeks ago, I filled up the tank of JORAN to assess how my miles could be covered till empty. That was on the 30th of March during the great big fuel panic. Admittedly the vehicle was not always used everyday of that week. On the 16th of April and after covering 439 miles I chickened out and refueled on the way to work. I also looked at my average FE over 2100 miles for overall drive style and it was 39.5mpg. This result included instances when I was not driving in a fuel focused fashion. It would appear more distance could have been covered with the remaining fuel but I could not chance a breakdown on the motorway so refueled. This got me wondering can a modern car be just as good on real world fuel economy? So I decided to find out and as I had a 2011 Focus and a new C max at my disposal it was a great time to see if the same type of driving could result in the best fuel economy. As with all these exercises there are some boundaries: Tanks were filled and the cluster, trip meter was reset. Both C-Max and Focus have 1.6 litre 125 and 105PS NASP TiVCT engines ( not this will matter for this exercise) I chose the C-Max and Focus as they are both C car like the Golf although they are 20years younger and fatter. I drove these cars in a fuel economy focused way similar to the drives on JORAN. No A/C was used, the blower and radio were used as in JORAN. So how did these modern vehicles do against the old NVH prone MK2 Golf 8v? Result Focus after 125 miles. Result C-Max after 61 miles. JORAN still undisputed at 51.7mpg on a 61mile trip! It should be noted the above modern vehicles are quiter, safer and heavier + packed with many toys as std. This would not be a norm even on the most spec'd up Mk2 GTi back in the day. So can an old 1992 Golf 2 8v GTI deliver RWFE by today standards. Most definitely
