MPG of different wheels and tyres?

[RobinGBrown]

I'm considering buying a Ct200H and while I understand that the real world mpg figures are more like the 40-50 range I have also heard that the smaller 16" wheels are more economical.

Does anyone have any actual figures real experience related to this rather than anecdotes? Any difference by tyre manufacturer too?

For reference I'm expecting to be doing about 4-5k miles of urban driving and maybe 2k miles of motorway driving per annum so it's urban mpg that's the primary issue.

[royoftherovers]

2 hours ago, RobinGBrown said:

I'm considering buying a Ct200H and while I understand that the real world mpg figures are more like the 40-50 range I have also heard that the smaller 16" wheels are more economical.

Does anyone have any actual figures real experience related to this rather than anecdotes? Any difference by tyre manufacturer too?

For reference I'm expecting to be doing about 4-5k miles of urban driving and maybe 2k miles of motorway driving per annum so it's urban mpg that's the primary issue.

Smaller wheels are more comfortable and economical.That is not anecdotal.

The number of miles you are doing per annum is such that you will not be saving much money,but I would advise Khumo` s a mid range with 69db rating or Michelin high range with 69db rating.

[Britprius]

I had a Prius on which the CT was based. The larger wheels with low profile tyres dropped the mpg by around 5 against using the smaller 205/55/16 wheels and tyres. I found that over 130,000 miles the best tyres for fuel economy, road holding, quite running, and ware life were Hankook. "I cannot remember the type name but it had green in it"
The next best tyres were Goodyear performance efficiency tyres, but these only lasted 18,000 miles against the Hankook 34,000 miles

The worst tyres on the car were the OEM Bridgestone Ecopia that were not fuel efficient, and got noisier as they worn to the point I thought I had faulty wheel bearings, but it was the tyres. I got rid of them at 15,000 miles. 

John.  

[RobinGBrown]

On 5/23/2018 at 6:15 PM, royoftherovers said:

Smaller wheels are more comfortable and economical.That is not anecdotal.

Do you have any references for that because I'd really like to find out more

[royoftherovers]

1 hour ago, RobinGBrown said:

Do you have any references for that because I'd really like to find out more

Google it Robin for yourself and do not overlook "Honestjohn.co.uk""

[Britprius]

As John above says the evidence is not anecdotal. Tyre pressures also have a big bearing on fuel consumption. Higher pressures in the same tyres bring a saving in fuel used. This is at the expense of ride comfort, and possibly road grip. Using the higher of the settings of those on the door jam label is probably the sensible pressure to use for economy.

There are other factors affecting fuel consumption such as wheel alignment, and sticking brakes "particularly sticking slide pins".  Warm weather also improves fuel consumption. On the Prius there was as much as a 10mpg improvement from winter to summer. Some of this is put down to the engine needing to run to provide cabin heat.

John.   

[XT5]

1 hour ago, Britprius said:

On the Prius there was as much as a 10mpg improvement from winter to summer. Some of this is put down to the engine needing to run to provide cabin heat.

John.   

And I believe the batteries are more efficient in warmer weather too aren't they?

[stormchaser]

I 2nd Khumos. I have them on the front of mine. I have Goodyears on the rear and they are very noisy.


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[RobinGBrown]

On 5/25/2018 at 8:03 AM, royoftherovers said:

Google it Robin for yourself and do not overlook "Honestjohn.co.uk""

Well I wouldn't be asking on here if I hadn't already tried to find out, I'm probably not using the right search terms

[ColinBarber]

On 5/23/2018 at 5:13 PM, RobinGBrown said:

I'm considering buying a Ct200H and while I understand that the real world mpg figures are more like the 40-50 range I have also heard that the smaller 16" wheels are more economical.

Does anyone have any actual figures real experience related to this rather than anecdotes? Any difference by tyre manufacturer too?

These are the official figures for the facelift models - S has 15" wheels, the others have 17" wheels. 16" would be somewhere in-between. You should be able to achieve an average above 50 mpg in a CT.

[RobinGBrown]

Thanks Colin that makes a lot of sense

 

[Wass]

Your query requesting hard data for MPG relating to wheels and tyres made me smile. Its just the same sort of question I had asked prior to owning a hybrid. By far and away the biggest influence on fuel consumption is the nut behind the wheel! Drive it like its stolen and it really doesnt matter what wheels and tyres you opt for or what the weather might be doing or whether you are on motorway or jammed up urban 20mph roads. Drive it at speeds and in conditions which suit its design for maximum efficiency and you will most likely be subject to a bit of road rage from other road users including pedestrians and cyclists and possibly might attract the attention of the forces of law and order too. ( using brakes in any way other than lightly has the potential to waste fuel---using them lightly puts power back into the battery). Manufacturers figures are in fact achievable. The conditions to achieve manufacturers figures very rarely occur on the roads but its something along the lines of travelling at between 30 and 40 miles an hour on roads which you know and can predict where to accelerate and brake whilst slip streaming a heavy lorry (which is restricted to a 40mph speed limit on single carriageway A roads) in warm  weather with a light  tailwind.

I would recommend the 16" versions because thats what my CT had. I do suspect that the 15" version is better ride quality, narrower profile and therefore smaller footprint/ more economical.

[ColinBarber]

2 hours ago, Wass said:

 (which is restricted to a 40mph speed limit on single carriageway A roads) 

That speed limit was upped to 50 mph two or three years ago now (expect for Scotland).

[RobinGBrown]

I'm wondering which is the most influential factor? Height of sidewall, size(weight) of wheel, or width of tyres? I'm assuming that the 15" wheels are more economical because of reduced width and weight?

[DanD]

Whatever the wheel/tyre combination, the overall diameter of the wheel has to remain the same so as to not compromise speedo calibration and the like. On that basis, if you fit bigger wheels, the height of the sidewall has to be reduced proportionally so that the overall diameter remains the same.

Comfort...
This impacts comfort, based on the fact that there is less rubber (in term of height) between your bum and the road, but also because the sidewalls need to be more rigid to prevent the metal from making contact with the road.

MPG...
Typically, bigger wheels are also wider. This translates in bigger footprint which should, theoretically at least, improve roadholding. However, larger footprint also means more friction, and more friction will result in lower MPG.

Same principle as thin tyres on a road bike vs wider tyres on a mountain bike.

[Desmond]

I've toyed with this problem over the years ever since manufacturers decided that filling the wheel arches with alloy and a thinner strip of rubber was a nice design feature. My first Avensis had a ride like iron so the next one had smaller wheels at my request and was a cracker both in ride and handling. The same applied when I got an IS 2.2D SE with all the trimmings, it was a lovely car but rode like a go kart.

I bought my 2014 model CT with 16" wheels and also got some cheap 16" alloys for winter tyres. When I got a new model in 2016 I couldn't get this with 16" wheels but in fairness the ride is pretty reasonable in the later model even with 17" factory wheels and low profiles. Some of this is down to better seats I think. When I put the winter wheels on it does make a difference though. The extra rubber does cushion the ride that bit more. Having said all that, subjectively, the handling seems more precise with the larger wheels, I don't notice any big difference in steering weight at low speeds either.

As far as economy is concerned, I average around 55 overall on the two sets of wheels but bear in mind that when the winter 16" wheels are on the car the ambient temperatures are a lot lower, so perhaps smaller wheels are compensating for this a bit.