Changing tyres and headlights

[Xariann]

I was toying with the idea of swapping my 15 inch wheels on my Yaris Icon with 16 inch wheels you find on the Design.

Question is - has anyone done it and how much has that affected MPG? I know it will be worse, but how much?

The other thing I was considering was changing the headlights to have the LEDs on top, like the Design. Is that very difficult?

In retrospect we should have probably bought a Design, not an Icon, but now we have the Icon so I was just looking at a couple of tweaks we can live without.

[Justhandguns]

I am not sure about the mpg differences. From my experience with the Aygo, I did not observe any significant increase when switching from the standard 14" wheels to the much wider 15" alloys. Some of the more experience fellows here may now more about this, but from what I heard is just a few % of increase in fuel consumption, unless you are drastically switching to ultra wide 17" tyres.

As for the daylight driving bulb, I just swapped it with some compatible LED bulbs, yes, it does not look as nice as the panel of LEDs, but at least it looks a bit more high-tech with the white light.

[FROSTYBALLS]

Have you checked with your insurance company whether they will accept the changes, or whether they will classify them as modifications - which may result in an increased premium ...

[Xariann]

1 hour ago, Justhandguns said:

I am not sure about the mpg differences. From my experience with the Aygo, I did not observe any significant increase when switching from the standard 14" wheels to the much wider 15" alloys. Some of the more experience fellows here may now more about this, but from what I heard is just a few % of increase in fuel consumption, unless you are drastically switching to ultra wide 17" tyres.

As for the daylight driving bulb, I just swapped it with some compatible LED bulbs, yes, it does not look as nice as the panel of LEDs, but at least it looks a bit more high-tech with the white light.

That's interesting. Do you have pics of the headlights by chance? ;)

And good to know on the tyres.

[Xariann]

29 minutes ago, FROSTYBALLS said:

Have you checked with your insurance company whether they will accept the changes, or whether they will classify them as modifications - which may result in an increased premium ...

I haven't checked, but considering previous experience I am almost positive the headlights will be classed as mods, while tyres is a question mark as I think on my Celica they weren't counted as a modification because they were a manufacturer option. I would try to go with the Toyota option but we'll see.

If I go down that route though I will check ;)

[bathtub tom]

If you change wheel and tyre size, you definitely need to tell your insurers of this significant change.

Try this website to determine your tyre size without adversely affecting your speedo: http://www.carbibles.com/tyre_bible_pg4.html

Just over halfway down gives you the difference in rolling radius of different tyre sizes

[Xariann]

Oh I didn't say I wouldn't check. I said I have precedence for insurance not changing my premium for using manufacturer tyres that were an option for the car :)

And I didn't realise that the speedo could be affected (unless you use the rule mentioned in the link). I had never thought of how the car calculated the speed.

Another thing I might have to adjust is the reverse camera.

[MEP's Yaris GS]

1 hour ago, Xariann said:

Another thing I might have to adjust is the reverse camera.

Why?

[Xariann]

Toyota says that if you change your wheels you need to make sure that the camera is still calibrated properly as the parking lines will be in a different place.

It obviously depends on whether the wheels will be bigger or not.

[Justhandguns]

18 hours ago, Xariann said:

That's interesting. Do you have pics of the headlights by chance? ;)

And good to know on the tyres.

 

I will try to take a picture later on.

 

18 hours ago, Xariann said:

I haven't checked, but considering previous experience I am almost positive the headlights will be classed as mods, while tyres is a question mark as I think on my Celica they weren't counted as a modification because they were a manufacturer option. I would try to go with the Toyota option but we'll see.

If I go down that route though I will check ;)

 

I thought it is the other way round? I am sure that if you change the size of your alloys, you will need to pay a higher premium for your insurance (depends on which insurer). As for the headlamps, unless you are changing the whole assembly or switching to some very bright HID system, switching a tungsten bulb to and LED should not matter. I would be more concerned if they are bright beyond the legal limit (which is unlikely). If you try insurance quotes for a Yaris with 15" wheels vs 16" wheels, you will certainly get a difference.

 

3 hours ago, Xariann said:

Toyota says that if you change your wheels you need to make sure that the camera is still calibrated properly as the parking lines will be in a different place.

It obviously depends on whether the wheels will be bigger or not.

I agree, if you either use a smaller or a bigger wheel, it will basically change the ride height of the car which effectively affect the reverse camera angle. 

[MEP's Yaris GS]

6 minutes ago, Justhandguns said:

If you try insurance quotes for a Yaris with 15" wheels vs 16" wheels, you will certainly get a difference.

Not with all companies, but most.

[FROSTYBALLS]

6 minutes ago, Justhandguns said:

I thought it is the other way round? I am sure that if you change the size of your alloys, you will need to pay a higher premium for your insurance (depends on which insurer). As for the headlamps, unless you are changing the whole assembly or switching to some very bright HID system, switching a tungsten bulb to and LED should not matter. I would be more concerned if they are bright beyond the legal limit (which is unlikely). If you try insurance quotes for a Yaris with 15" wheels vs 16" wheels, you will certainly get a difference.

I agree, if you either use a smaller or a bigger wheel, it will basically change the ride height of the car which effectively affect the reverse camera angle. 

Whether or not the ride height changes depends on the wheel/tyre combination rather than just the wheels.

As regards insurance, a change form the standard spec is enough for some insurers to either charge an extra premium or refuse cover. An example is the following extract from another thread: I would like to point out to members again, that Toyota Insurance do not accept a change of wheel size from original specification. I have a 2012 Auris HSD T-Spirit with 17" wheels, and enquired about fitting 15" wheels and appropriate tyres for the winter. Toyota insurance will not provide cover for this change. 

Rather than assume, it is best to check with one's insurer first.

[Xariann]

Right.

I would like to point out a few things:

1. I am not with Toyota Insurance

2. I was asking about MPG, not about how an insurer would react

3. I said a couple of times now that if I decided to do modifications I will check with the insurance, all I have said is that when changing wheels to the Celica the insurance had not charged me extra because they were an option you could get from factory, but never have I said I will try to get away without asking; what I wanted to know was the impact on my MPG specifically

Hope that clarifies :)

[FROSTYBALLS]

No-one has implied you are with Toyota Insurance - the example I gave of an insurer refusing cover just happened to be Toyota Insurance.

The effect on mpg will depend not only on the weight of the larger wheel, but also on the size tyre (the profile) used, and how that equates to the original wheel/tyre combination.

[Justhandguns]

1 hour ago, FROSTYBALLS said:

No-one has implied you are with Toyota Insurance - the example I gave of an insurer refusing cover just happened to be Toyota Insurance.

The effect on mpg will depend not only on the weight of the larger wheel, but also on the size tyre (the profile) used, and how that equates to the original wheel/tyre combination.

I think most of us who go/went for bigger alloys would just keep the same tyre diameter as the original spec. i.e. in 2016 Yaris 175/65/15" 195/50/16". 

I would think that the friction from wider tyres would have a more significant effect on the mpg. 

[Xariann]

1 hour ago, FROSTYBALLS said:

No-one has implied you are with Toyota Insurance - the example I gave of an insurer refusing cover just happened to be Toyota Insurance.

The effect on mpg will depend not only on the weight of the larger wheel, but also on the size tyre (the profile) used, and how that equates to the original wheel/tyre combination.

It's just that all the focus on the insurance was going slightly off-topic, and I had mentioned what /my/ insurance had done before.

I appreciate the input though and the fact that people are looking out for things I might have not considered.

[Xariann]

13 minutes ago, Justhandguns said:

I think most of us who go/went for bigger alloys would just keep the same tyre diameter as the original spec. i.e. in 2016 Yaris 175/65/15" 195/50/16". 

I would think that the friction from wider tyres would have a more significant effect on the mpg. 

That's what I wanted to do in terms of wheel size if I decide to go with changing wheels.

[FROSTYBALLS]

Provided one uses the same wheel/tyre combination as the Design, one can get an indication from the Official EU consumption figures stated in the brochure -

Combined & Extra Urban: 78.5 (16' wheels) - 85.6 (15' wheels)

Urban 85.6 (16' wheels) - 91.1 (15' wheels).

So as a rough guide one may lose up to 7mpg.

 

[Justhandguns]

10 minutes ago, FROSTYBALLS said:

Provided one uses the same wheel/tyre combination as the Design, one can get an indication from the Official EU consumption figures stated in the brochure -

Combined & Extra Urban: 78.5 (16' wheels) - 85.6 (15' wheels)

Urban 85.6 (16' wheels) - 91.1 (15' wheels).

So as a rough guide one may lose up to 7mpg.

Ah, that's true, I forgot that they do have this piece of info. But I doubt that there is such a big difference in practice.

[MikeSh]

175 to 195 is a 20mm wider tyre, so there will be a little extra drag, but I'd be surprised if you'd lose 7 mpg.

Mind you, those official figures look about double what you'd likely get, so 3.5 mpg loss might not be a silly number to assume.

[FROSTYBALLS]

4 minutes ago, MikeSh said:

175 to 195 is a 20mm wider tyre, so there will be a little extra drag, but I'd be surprised if you'd lose 7 mpg.

The quote was 'up to' 

[MikeSh]

23 hours ago, FROSTYBALLS said:

The quote was 'up to' 

OK, mine was poorly worded. I think you might lose up to 3.5 mpg.

I still doubt it would be that much and any difference would be hard to see for sure in the general variations of mpg you get over time. If you were really concerned about mpg then it would be more sensible to use a larger diameter wheel but still use a 175 tyre (ensuring the wheel width is suitable).

However, if you were spending several hundred ££ fitting larger wheels just to look good I rather doubt a few mpg is going to matter you ... 

[Xariann]

12 hours ago, MikeSh said:

OK, mine was poorly worded. I think you might lose up to 3.5 mpg.

I still doubt it would be that much and any difference would be hard to see for sure in the general variations of mpg you get over time. If you were really concerned about mpg then it would be more sensible to use a larger diameter wheel but still use a 175 tyre (ensuring the wheel width is suitable).

However, if you were spending several hundred ££ fitting larger wheels just to look good I rather doubt a few mpg is going to matter you ... 

For me it's more about trying to avoid using more non-renewable fuel. :) It sounds like the MPG difference will be minimal though.

If I had the parking space and the ability to fit a charging point by the house I would go full electric. 

But fuel economy doesn't have to mean no style!