Optimal cruising speed

[Scrozzy]

Hello chaps,

My first post, and I ran a few wee searches but I couldn't come up with anything.

I'm driving from North London to the arse end on nowhere in Wales on Wednesday, and I wondered if anyone knows what the optimum cruising speed for a Leon Cupra is (180bhp) in terms of getting the best mpg? It would come in handy for the M4 methinks.

I've looked at the power band graph for the torque/bhp, but I'm not sure how to interpret that graph in order to ascertain the best economy because I'm such a n00b.

Cheers in advance.

 

[CupraSteve]

50mph in top gear on average is the most efficient speed to travel

 

[Scrozzy]

Buggerit, really? What sort of mpg will that get then? I remember getting better economy by crusing @ 80 instead of 70 once, but I can never quite work it out. I also remember getting 45mpg out of a 2.0 Corrado when I was slipstreaming behind a lorry doing 50mph up the A1 ...

I really should just go back to a diesel ZX, eh.

 

[vwsurfbum]

50mph is what they do to get the official fuel figures in the mags.

 

[matt_s]

Just be gentle on the throttle. Don't go screaming up behind people and then accelerate past when they move over. If you take it easy then you should see some improvement. Remember to check the tyre pressures before you go and don't use the aircon unless you have to.

If you have the patience just sit behind a truck and stay at a nice constant speed.

Personally I don't, I'd rather just get there.

 

[WaveyDaveyGravy]

I've got a diesel LC but I'd imagine the basics are the same... I find that in heavy traffic I get 50mpg+ rather than 45 'pressing on'. I think there is quite a big difference between averaging 70 and 80 (on private roads m'lud!)

Also keep your windows closed, air-con off and make sure your tyres are inflated properly. I'd personally recommend a psi or two extra if you are stuck on the motorway as it cuts rolling resistance and you don't really need huge cornering grip.

 

[RikH]

between 50 and 60
id think at 50mph across say a steady 200 miles id be guessing about 37mpg?
who knows becuase the trip computer lies anyway to make you feel better

 

[CupraSteve]

I've got a diesel LC but I'd imagine the basics are the same... I find that in heavy traffic I get 50mpg+ rather than 45 'pressing on'. I think there is quite a big difference between averaging 70 and 80 (on private roads m'lud!)

Also keep your windows closed, air-con off and make sure your tyres are inflated properly. I'd personally recommend a psi or two extra if you are stuck on the motorway as it cuts rolling resistance and you don't really need huge cornering grip.

then youl be shelling out on tyres as you wear out the centers lol. So your no better off

 

[jmcvicar]

Anything over 80 causes a big drop in mpg (as do frequent presses of the loud pedal for overtaking etc).

I regularly travel to Leeds/Newcastle from the south-east in mine and average around 33-35mpg. I've given up trying to get the best mpg and just make sure I enjoy the journey Usually get around 370-380 from a full tank.

 

[andycupra]

there is a fair drop off in MPG figures from 70 to 80!

i think around 50mph is the best for good MPG on the leon cupra.
high 30's.

one good way to get better economy is to think that everytime yo use the brakes you have wasted fuel..
so other than when you are actually stopping if you can adjust your driving so you dont use the brake you will get a good improvement.
however dont forget to use the brakes completely, or you wont be worrying about fuel costs!

ps best mileage i ever got on my leon cupra was on a1 with a series of roundabouts. seems the gain from coastin up to them is more than the cost of accelerating again.

 

[psq43]

Scrozzy,

if you got cruise then usualy find that an INDICATED 77 mph (shows as 112-114kph on climate display code 26) is the nest compromise between fuel economy and being a dangerous moving chicane, given my intimate knowledge of the M4. You dotn want to be going any slower than 70 unless you want to end up on the news as the lastest victim of the junction 15-16 stretch!

 

[psq43]

And if you dont got cruise, try to carefully monitor what your right foot is doing! Constant speeding up and slowing down without really noticing (even just 4-5 mph over or under) can burn off so much extra fuel!

 

[WaveyDaveyGravy]

then youl be shelling out on tyres as you wear out the centers lol. So your no better off

Got 20k from my front Contis so not really a problem - still lots on rear too. I run 34psi all round, sharpens turn in and improves economy, but does give less grip. But not a hooligan so not really a problem!

 

[LC1980]

I occasionally do Leeds to Brighton (265 Miles) and on my last trip i used half a tank of motion lotion and was indicated 38.9 Mpg for the journey. I have a LCR 225 and found the most economical cruising speed to be just shy of 80Mph, this seems to be enough pace to pass lorries and slower traffic without needing to accelerate to get passed them.

 

[psq43]

I occasionally do Leeds to Brighton (265 Miles) and on my last trip i used half a tank of motion lotion and was indicated 38.9 Mpg for the journey. I have a LCR 225 and found the most economical cruising speed to be just shy of 80Mph, this seems to be enough pace to pass lorries and slower traffic without needing to accelerate to get passed them.

so this would go with my theory above then! Glad it not just me!