Hi,

I've been trying to get the best fuel economy from my 1.4 8v 2000 reg Fabia. I've managed to get 45mpg for my daily commute, it's mostly on 50 mph dual carriage way, and today I experimented with going into 5th gear when cruising along long stretches at 30 mph. I'm only changing up once i hit 30 and using 3rd & 4th to accelerate if it drops, never using 5th for acceleration. I find that doing this can give me a current (not average for the trip, but mpg at that moment) mpg of up to 70mpg!

Now my question is this, does using 5th gear for maintaining a speed of 30mph damage the engine or cause any other problems I should worry about In this type of car/engine?

Thanks

Lou

I'm not sure I'd trust any MPG display on the dash. Best method is to brim the tank, drive, then brim the tank and the amount of fuel you just used can be used with how far you travelled since filling up to calculate mpg. You can use a website like fuelly or spritmonitor to help keep track. I'd generally keep 5th for 40mph myself. So long as it isn't making the engine struggle I can't see it would be a problem. In fact, as you mention it I might give it a go myself

I've found the biggest factor for MPG in the 1.4mpi seems to be the top speed you travel at. If I go an indicated 65mph (about 60mph in reality) I get noticeable benefits compared with doing an indicated 75mph. I chose 65mph as this seems to keep you at a good pace without lorries having to overtake etc. I wonder if cruising slower would give further benefit.

Edited 19 July, 201015 yr by anewman

The engine doesn't seem to struggle at all when doing 30mph in 5th, as long as i'm not accelerating. I think I might keep it up for a few more days, see what the out come is.

You mentioned not trusting the speedo, I've noticed that on my garmin satnav when I reach 70 on my speedo it's only really about 63 ish, i don't actually hit 70 on the satnav until my speedo reaches around 77! I'm not quite sure which to trust more, I've read good things about satnv speedo due to actually recording real distance travelled, not size of wheel rotating x times per second.

I was also thinking of getting cruise control installed at some point, maybe this would help keep at 65ish?

Thanks

Lou

Somehow I managed to get 51 mpg on my commute to work, not bad for a 15 mile run in London, eh?!

Cruise control may well lower MPG, as it won't coast down hills or plan ahead as a human can do.

45mpg is around what my old 16v 1.4 did - which I think is meant to be better on petrol, so good going there!

i would have thought that cruise control would atleast come off the throttle when going downhill, although the planning for other drivers would be a bit too tricky for it

It's weird, 'cos although I managed 51 mpg on the commute to work, I barely scraped 44 mpg on the way home. The traffic wasn't particularly worse and only had aircon on for about 10 mins, maximum (30 min journey)

Gotta admit it's quite addictive, driving with the journey mpg readout up all the time! Might have to look at some hypermiling techniques!