Is it possible to get to Cornwall on one full tank of petrol?

[HappyChappieDappe]

Specifics are, travelling from East Anglia to St Ives, Google maps says 329 miles, up to 5.5 hours drive.
Car is a relatively new Dacia Duster, full petrol capacity is just over 300 miles I think (never put a FULL tank in)
Is it doable? or will I need to fill up part way through? (Obviously will fill up on the way back)
Just want to get the logistics defined as will be travelling with a small child who will need a couple of comfort breaks.

How can it only be 5.5 hours drive from East Anglia to St Ives? I think that's totally wrong!

Id say fill up part way just to be safe, even if you just chuck 20 quid in.

My route to Cornwall is 386 miles, and i top up just in case part way down the M5.
My car when full usually reads 398-404 miles in the tank but it wouldnt make it all the way.

This will be fine because you'll be going south which is downhill.

5.5hrs drive sound very wrong. Over 2hrs of that is from Exeter to St Ives....

I wouldn't think so now, and I guarantee it won't be 5.5 hours.

Just put my postcode in and the resort postcode and it says 5 hours 54 minutes to be exact.

Refuel at one of your rest stops. You'd be cutting it very fine, may not be a handy petrol station at your destination, and always a significant possibility of delays.

Why on earth not, you'll have to refill to use the car while you're there and then to return home.

You will need to stop anyway so factor your stops in - decide whether you'll come off and go to a small town/village and tie in one with a petrol station or use the services.
I wouldn't want to stress about making it so I'd plan to top up a little bit to tide me oover rather than hope for the best.

If your 300 mile range is what you get from normal 'around town' driving then yes, as you'll likely get better MPG on a long journey as long as you don't drive excessively fast.

How big is the tank? My car has the smallest tank of all the cars I've ever driven at 35 litres and I never get less than 350 miles from a tank, so I'd expect to get there without having to fill up.

However, you will stop on the way there at least once, likely twice, so I think I would plan on filling up on the second stop, then you'll have enough for driving around while you're there and possibly starting the journey home. Then when you fill up on the way back, you'll definitely get home and have enough for a few days normal driving too.

If the roads are clear and you're on a motorway you'll probably find your car can do closer to 400 miles on a tank. But the journey to St Ives is rarely clear and a lot of it isn't motorway so I'd recommend filling up at some point along the way. If you're traveling at any point during school holidays then expect it to take way longer than five and a half hours.

We do it in about 3 hours from where we are in Hampshire with no stops and leaving at about 5am.
We don’t need to stop for fuel but it you’re planning on stopping anyway for the dc then surely just stop at a fuel station?!

You will easily get there on one tank. On a run the range is likely to be closer to 500 miles. You have an 11 gallon tank and you’re likely to achieve 45-50mpg, I’ll let you do the maths.

What's the dilemma? Find somewhere about 2/3 of the way that has a petrol station and a nice cafe or something for a leg stretch and toilet break for your child.

If you end up needing to stop at a service station for a wee before that planned stop but don't want to pay motorway petrol prices then just stop again.

I don't get why this needs such planning or you'd consider risking getting there on fumes.

I'm a little closer (Herts) but always do the journey and have petrol left in my tank at the end (hatchback).

Unless you leave in the dead of night, it will take you nearer to 7 hours or even longer... I've only done the journey in under 6 hrs if I leave at 2am.

So 6 hours then.

Plan a couple of stops. Top up your fuel on the way. Get off the motorway and visit a normal supermarket, use the cafe and pay normal fuel prices.

I'd never risk running out - you could be sat in static traffic for hours after a serious incident and find yourself cold and in trouble.

@Shade17 but not all of it will be motorway driving. East to South West isn't served well by motorways

From West of London (near Heathrow) the journey took us 7.5 hours last May. I think we have done it in 5, but you are much further away than we are.
Have a look for slightly off route petrol stations rather than paying extortionate Motorway prices.

Have you thought where you might take breaks @HappyChappieDappe It's still a trek once you get to Exeter and off the M5

You only get 300 miles out of a tank of fuel? Is that petrol? I get 600+ out of my euro 6 diesels which would be plenty for Cornwall and back - and the whole holiday in between.

You’ll find your fuel consumption goes down on long runs so if you 300 miles in round town you’ll increase that a lot on the motorway.

Even so, the fuel economy is not likely to drop much below that. I was being very conservative in my figures, it wouldn’t surprise me if 60mpg was achievable on the motorway. There is no chance that they’ll come even close to running out.

No, but the A30 is now dual carriageway from Exeter to Hayle. So it's a big improvement.

I was planning to stop off at Winchester services then Exeter services on the way in any case. It's just over 2 hours between each (of course not factoring in half term traffic!) It was just a general question is all, of course I wouldn't risk my car conking out because I didn't fill up.

Currently debating whether to travel overnight with DD or crack of dawn like 5am!

You probably/possibly could manage it on one tank but you would arrive with an empty tank. Surely it would be better to fill up when you are 3/4 of the way there so you have a full tank for your stay and start of the journey back?

Depends when travelling. A30 seems to be constantly congested with overturned caravans during the summer weekends!

Definitely plan to fill up, you can use the petrol prices app to find somewhere cheap en route (don't pay service station prices). Far better to fill up than be stressed that you might not make it. I try to not let my car go below about 50 miles left in case of emergencies after needing to do an A&E run (10 miles away) at 5am and finding my car already with the fuel light on.