Very slight steering judder at motorway speeds...

[J1990]

So, I'm not sure if this is something that's entirely in my head or if there's something specific I need to get checked out. My intention is to book in for it looking at but just trying to work out some possibilities to steer where I book in at. It's worth noting that when I say slight judder, I really do mean very slight vibration/judder.

The car is a 2021 Hyundai Tucson, with a rather invasive Lane Keep Assist and steer assist that means that the vast majority of time driving at motorway speeds you're holding the steering wheel but not doing much steering yourself.
I recently had all four tyres replaced and since then I've noticed that the MPG seems to be significantly worse (15-20%) which was the first thing I'd noticed, I'm also aware the weather has been a bit colder and wetting since the change, along with going for rainsports for better wet grip so aware that doesn't help things but then when on a motorway drive I felt like once up at 60-80 there was a very slightly judder on the steering wheel. Turning off all driver assists and loosening my grip on the wheel didn't show any any pulling to one side or the other, a check of tyre wear doesn't seem to show any of alignment issues and I can't help but wonder if the small vibration has always been there and I've just never noticed.

There's no noticeable vibration at low speeds, nothing under acceleration or braking, no stones or similar stuck in the treads and I'm generally a bit baffled.
As I said, I'll be booking it in so that it doesn't keep bugging me but I thought I'd see if there were any suggestions of what could potentially have such a tiny effect in terms of how much I can feel it on the steering wheel but potentially have a sizeable impact on the efficiency, so likely increased drag?

[Scrump]

Have you checked tyre pressures? (Low pressure can cause an increase in fuel consumption).

As you just had new tyres fitted, I would guess the slight vibration likely to be one of the wheels not balanced perfectly

[J1990]

Scrump said:

Have you checked tyre pressures? (Low pressure can cause an increase in fuel consumption).

As you just had new tyres fitted, I would guess the slight vibration likely to be one of the wheels not balanced perfectly

Yup, tyre pressure is fine all around. Imbalanced front wheel was one of my first thoughts for the vibration and may just be coincidental about the MPG. It just seems quite a dramatic drop in mpg (From averaging 40-45mpg on a motorway cruise to getting 33-35mpg)

[Far Cough]

Scrump said:

Have you checked tyre pressures? (Low pressure can cause an increase in fuel consumption).

As you just had new tyres fitted, I would guess the slight vibration likely to be one of the wheels not balanced perfectly

If nothing else has been touched then it will be either of these. My money will be on the wheel out of balance. Go back to the place that fitted them and ask them to check. New tyres need to bed in which may account for your increased mpg

[andygo]

Far Cough said:

If nothing else has been touched then it will be either of these. My money will be on the wheel out of balance. Go back to the place that fitted them and ask them to check. New tyres need to bed in which may account for your increased mpg

Why do new tyres need to bed in and why would the MPG drop please?

[E-bmw]

andygo said:

Far Cough said:

If nothing else has been touched then it will be either of these. My money will be on the wheel out of balance. Go back to the place that fitted them and ask them to check. New tyres need to bed in which may account for your increased mpg

Why do new tyres need to bed in and why would the MPG drop please?

They don't, ignore.

[andygo]

E-bmw said:

They don't, ignore.

I know, but thought I'd ask, lol.

[Far Cough]

https://www.merityre.co.uk/tyres/tyre-safety/drivi...


https://www.energy.gov/energysaver/tires-and-fuel-...

Obviously just ignore the facts it if you like .... LOL

Edited by Far Cough on Wednesday 17th January 08:58

[E-bmw]

Yes, but that isn't really "running in" the tyres, is it, it is removing the release agents from the surface of the tyre & isn't going to affect MPG as it was suggested it would?

[Far Cough]

Read the 2nd link. A brief copy of one of the relevant bits :

"Tire treads can impact your fuel economy because 35-50 percent of the rolling resistance of a tire comes from the tire tread. Some tread compounds can reduce rolling resistance a great deal. In addition, the shallower the tread, the more fuel efficient the tire will be. So if you can achieve traction, the more fuel-efficient tires might be shallow-tread rib designs. Unlike race car drivers, who use tires with no tread because they provide less resistance and allow their vehicles to more easily achieve higher speeds, the average driver needs tread to help the vehicle easily brake when the weather is bad. Use the proper type of tire for the type of driving. For instance, using chunky tires suited for off-roading for urban driving will significantly decreasing fuel efficiency."

You can split hairs about calling it running in or bedding in but essentially it's the same. A tyre is not at 100% until a few miles are put on it.

If the OP has swapped from bald tyres with a low rolling resistance to brand new with chunky tread then his mpg will increase which is what he asked. Put an extra 10psi in them and all of a sudden he will see higher mpg. It's science, physics and to a degree chemistry where the actual tyre contacts the ground...... I'll bore off now.

[rev-erend]

With the state of our roads it could be a damaged tyre or wheel. Get them checked.

[MustangGT]

Far Cough said:

Read the 2nd link. A brief copy of one of the relevant bits :

"Tire treads can impact your fuel economy because 35-50 percent of the rolling resistance of a tire comes from the tire tread. Some tread compounds can reduce rolling resistance a great deal. In addition, the shallower the tread, the more fuel efficient the tire will be. So if you can achieve traction, the more fuel-efficient tires might be shallow-tread rib designs. Unlike race car drivers, who use tires with no tread because they provide less resistance and allow their vehicles to more easily achieve higher speeds, the average driver needs tread to help the vehicle easily brake when the weather is bad. Use the proper type of tire for the type of driving. For instance, using chunky tires suited for off-roading for urban driving will significantly decreasing fuel efficiency."

You can split hairs about calling it running in or bedding in but essentially it's the same. A tyre is not at 100% until a few miles are put on it.

If the OP has swapped from bald tyres with a low rolling resistance to brand new with chunky tread then his mpg will increase which is what he asked. Put an extra 10psi in them and all of a sudden he will see higher mpg. It's science, physics and to a degree chemistry where the actual tyre contacts the ground...... I'll bore off now.

I would be taking that quote with a large pinch of salt from reading the bit I bolded. Racing tyres (dry weather) have no grooved tread because the increased rubber surface area gives better grip, not to achieve higher speeds.

[Far Cough]

MustangGT said:

I would be taking that quote with a large pinch of salt from reading the bit I bolded. Racing tyres (dry weather) have no grooved tread because the increased rubber surface area gives better grip, not to achieve higher speeds.

There is a bit of American cheese in that link I posted but the basics are there. I couldn't be bothered to type it all out for the un educated.

[MustangGT]

Far Cough said:

MustangGT said:

I would be taking that quote with a large pinch of salt from reading the bit I bolded. Racing tyres (dry weather) have no grooved tread because the increased rubber surface area gives better grip, not to achieve higher speeds.

There is a bit of American cheese in that link I posted but the basics are there. I couldn't be bothered to type it all out for the un educated.

That American link has some of the worst (incorrect) information I have ever seen relating to tyres.

The OP has changed from low-tread to new tread, we do not know whether he changed brands or not. Unless he went from road tyres to All-Terrain he should not really be seeing an increase in fuel consumption in the order of 25-20%. Changing like for like will make very little difference at all, especially given you actually gain around 1.5% in distance travelled per revolution when replacing the tyres due to the larger circumference of a new tyre.

Different brands and tread patterns come with an inherent consumption level, that is why the Euro tyre information is given so that you can compare. Any two tyres of the same size showing the same grade, let's say 'B' will be very close in fuel consumption.

Consumption change with road tyres is mostly affected by two things, tyre pressure and weather conditions. In general, keep the tyres at the correct pressure and drive in generally good weather will see the best outcome in consumption.

I fully agree with your first link in that new tyres need to be treated carefully for 150-200 miles, I also note there is zero reference to a change in fuel consumption during that period (because it makes no difference to fuel consumption).

[wyson]

I had this after a tyre change. Nothing at slow speeds, a slight vibration kicked in around 70mph. It was one of the front wheels slightly out of balance. The tyre fitter spent 20 minutes rebalancing it, seemed to fit a dozen weights to it. Kept putting it on the machine, adding a weight and scratching his head. Honestly never saw that many wheel balancing weights on one wheel before. Was scared the wheel trim would fly off because it wouldn’t seat properly. But it stopped the vibration. And because I went back a week after the initial fitting, they rebalanced it for free.

Edited by wyson on Saturday 20th January 08:50