Michelin crossclimate 2 mpg

[russvphoto]

I’ve just put these on my T32, size 275/40/20 and my fuel consumption has suddenly dropped from 38mpg to 30mpg on my 1000 mile motorway drive from Scotland to Portsmouth and back. I’ve done this trip a few times in all seasons and 38mpg was always the norm. Anyone else experience a drop in mpg?

 

[Crazymind]

I don’t think it’s the tyres. I think it’s the temperature outside. In the summer from
glasgow to Folkestone I can get 38/40mpg, at this time of the year it’s down to 30/32mpg. I have got same tyres as you, Crossclimate 2. 8 k miles on it now.

 

[Pete C]

Are the tyres the same size as what was on previously ?

Pete

 

[russvphoto]

Are the tyres the same size as what was on previously ?

Pete

Yes they are.

 

[moomin-j]

I’ve just put these on my T32, size 275/40/20 and my fuel consumption has suddenly dropped from 38mpg to 30mpg on my 1000 mile motorway drive from Scotland to Portsmouth and back. I’ve done this trip a few times in all seasons and 38mpg was always the norm. Anyone else experience a drop in mpg?

@VanDamMan

Have you got these tyres on your ride and have noticed reduced MPG?

 

[DaveCrampton]

Crazymind is right, cold air is more dense, so your van is pushing more of it out the way when moving.

 

[russvphoto]

I don’t think it’s the tyres. I think it’s the temperature outside. In the summer from
glasgow to Folkestone I can get 38/40mpg, at this time of the year it’s down to 30/32mpg. I have got same tyres as you, Crossclimate 2. 8 k miles on it now.

Interesting, I'll have to see as I've done the journey 4 times, 2 in summer and 2 at Christmas on the old tyres and I'm sure the mpg was the same 38mpg but thanks for your input.

 

[Green Giant]

Cold weather/air definitely makes the engine more thirsty, plus in winter we have a lot more electrical items switched on which also makes the engine work harder, I loose about 4 mpg when I put the winter tyres on the car and that’s just the tyre design, then every driver, regardless of what tyres are fitted has reduced MPG in the colder months, and it takes a big hit in the extreme cold like we had in the weeks before Christmas

 

[VanDamMan]

@VanDamMan

Have you got these tyres on your ride and have noticed reduced MPG?

Hi @moomin-j ….yes I’ve got this tyre but not noticed a MPG drop….But the tyre never claimed to be a low Profile type that saves fuel being low resistance……Overall I get better grip on cornering and less wheel spin on soft wet ground and since using more confidence in the vehicles ability in most conditions….but mine are 18’s at 255…..so if you use a wider profile you’d get more resistance on the road that would increase drag….Cross climates are not low profile and it’s a trade off from efficiency to practicality……as the tyre states a Tyre for all seasons…..I love them

Ps tyre pressures need to be adjusted to conditions/seasons to achieve better efficiency overall….

 

[DXX]

Air Density Calculator | What is Air's Density?

Use the online air density calculator to find out the density of air at any given temperature and pressure.

www.calctool.org

The cooler the air the more dense it gets but the difference is not significant over the UK temperature range.
MAF sensor is monitoring the air inlet temperature and fuel is delivered accordingly, in a situation where max’ power is required the cooler the air the more power is available. Unless a van is being driven foot to the floor this won’t make a difference.
Tyre rolling resistance will make a significant difference and the tyre pressure monitoring has a 25% alarm limit from set point. I’ve found that the TPM is great for spotting a puncture but no use whatsoever for general tyre pressure checks.
Reduction in ambient temperature will obviously reduce the tyre pressure and increase rolling resistance.

 

[Ayjay]

I know it's not a VW van but I've got those tyres on my Audi Q5 and there wasn't any drop in consumption when I changed.

 

[Crazymind]

any update?

 

[russvphoto]

Last weekend I had 30mpg early morning and 38 after 11am. It does seem they’re very temperature dependant. My old cheapy tyres returned 38 mpg consistently.

 

[t0mb0]

Last weekend I had 30mpg early morning and 38 after 11am. It does seem they’re very temperature dependant. My old cheapy tyres returned 38 mpg consistently.

How are you measuring mpg twice in the same day? The only method that’s reliable is to fill the tank, and then top up again but I assume you’re not doing three trips to the filling station in the same day?

 

[russvphoto]

How are you measuring mpg twice in the same day? The only method that’s reliable is to fill the tank, and then top up again but I assume you’re not doing three trips to the filling station in the same day?

I was going by the figures on the dash display.

 

[t0mb0]

I was going by the figures on the dash display.

Ah, I really wouldn't take those too seriously! If you want to know MPG, the only real way is to note mileage between fills and work it out - probably a load of apps for phones etc that log it for you.

 

[Pete C]

We get significantly improved mpg with our winter tyres compared to our summer tyres, according to the dashboard display.
The real reason for this is that they are a slightly different circumference, which of course the van doesn't know.

The only truly accurate way to measure mpg is to do a known mileage (not measured by the van speedo) and then refill the van.

Pete

 

[dubber36]

We get significantly improved mpg with our winter tyres compared to our summer tyres, according to the dashboard display.
The real reason for this is that they are a slightly different circumference, which of course the van doesn't know.

The only truly accurate way to measure mpg is to do a known mileage (not measured by the van speedo) and then refill the van.

Pete

This is spot on. My wheels and tyres are 3% larger than the originals, so I'm actually travelling 3% further than the van is registering.

That said, my speedo now reads pretty much bang on with GPS. This has made the mpg on the computer closer to the figures worked out with maths.

 

[russvphoto]

My main thing is I used to get to Portsmouth with 20 miles to spare on my journey from Scotland on a full tank and now I have to fill up 10 miles south of Oxford to get to my journeys end.

 

[t0mb0]

My main thing is I used to get to Portsmouth with 20 miles to spare on my journey from Scotland on a full tank and now I have to fill up 10 miles south of Oxford to get to my journeys end.

I get about 36mpg (LWB 150 DSG loaded camper) on long runs on crossclimates but then I'm running a much less extreme tyre size than you (235/55/17 @ 48psi).