Quote:
Originally Posted by sinclair
I'm running a stock AX 1.5 on 50-75% veg oil at the moment and getting 75 mpg (imp) or 3.8 l/100km so I have some way to go. I have an air leak into the fuel line to track down at the moment but once that's sorted i'm back on the MPG case. Weight to loose, gaps to seal and an alternator to loose.  |
Hi fellow AX owner.
3,8 is already a nice start. I'm looking forward to your alternator deletion, it's also on my list of things to test one day.
Quote:
Originally Posted by mikeyjd
Nice Work!
|
Thanks, and it's just the beginning.
____________________
My flow measurement device is amazing.
A few months ago, my preheating box was down so I had to warmup the glowplugs under the hood manually. Meaning I couldn't do engine off starting : there is a 500 m slight decline where I started to roll with the engine off before starting at a red light. I was able to see that these 500 m done with the engine on consumed 130 mL (cold engine + idle at red lights) resulting in an 0,15-0,20 l/100 km average improvement on my total 80 km day trip. It was unexpectable for me that such a small part could affect that much the global consumption.
I could also highlight the different efficiencies. On the flat, my average consumption was 3,05 l at 75 km/h average = 20,7% engine efficiency. On a 8 km climb at 2,5% average at the same speed, my average consumption is only 3,51 l (about 80% throttle in 5th gear at 1900 rpm), that makes a 35% efficiency. And when I go the same part downhill I do EOC, I get 1,03 l/100 km (have to turn the engine on on some flats). The average of uphill and downhill is 2,27 l/100 km for 75 km/h, which is way less than what I get on the flat confirming that pulse&glide or hills can get better mpg.
The big tires helped FE but not as much as expected. They returned an average 3,05 l/100 at 75 km/h vs 3,14 for the original ones. I think I underestimated the aero impact of such big tires (car is 27 mm higher on the front also). Besides, they got only 0,0099 on a Cr test in the same conditions as last time where I got 0,0095 with my OEM tire. They are supposed to be 2 classes better than my 155s (B vs E). Strange...
One thing is sure, reducing RPM helped a lot : worse Cr, worse CdA and yet better FE. I won't keep these tires also due to the fact that I had to move my bumper to make them fit but they are not lost for everybody though, my dad will take them for his 305. I will probably test 145/80 R14 (cheap 2nd hand first) next, they are 7.4% bigger which might be the biggest possible without touching the bumper.
Changing the 5th gear is always nearer. Before changing, I have to do FE tests at constant speed in the last gear (30 to 110 km/h).