Do the mileage figures make sense?

Old test, there's new technology around that IS getting the winter certificateMichelin CrossClimate launched is this a game changer - TyreReviews
Goodyear Vector 4Seasons Gen 2 Press Release - TyreReviews

 

From what I've read they say Dunlop Enasave, and as someone who had driven on one for 500mi (comes OEM on Mitsu Mirage) can say for sure, it is the biggest POS you can find. Mirage managed 0.73 on skid pad, and 80% is due to Dunlop LRRs. Switching them out to normal tire (unfortunately there isn't any other LRRs) in Mirage size, had shown more than 10% MPG loss, so they are very good at LRR at expense of grip. Dunlop LRRs are rated AA in LRR and C in grip by Japanese tire rating system, and the best LRR Bridgestone EP001S rated AA/A in Japan and A/A in EU labeling system.

 

i think it's because the '16 is based on the new epa test, while the '15 wasn't.well, we know about the weight difference, the rear wiper and the tyres model and higher inflation. it doesn't take that much to gain 4 mpg, but there might be something else toyota hasn't told us yet.

 

I know new candidates did very good (GoodYear, Michelin, Nokian), but the problem is:
- they are pricer (80€ per set difference)
- after 2 years (44k km) winter traction would be questionable
- fuel consumption would be around 0.2 l/100 km higher
- still not optimum for 50°C tarmac in summer or -20°C in winter (tire tests are not done in extreme conditions)

With two sets I get:
- better traction
- better longevity per tire
- better fuel consumption

Both options cost about the same (tire change costs me 25€) if you are doing 20k km/year, the less km you drive all season option looks better and vice-versa.

 

this is misleading it is still the same test. EPA just issued guidelines on how it should be executed. So if you weren't cheating in a first place like Hyundai or Ford there will be no difference. Or you think Toyota cheated too?

 

This is not completely accurate.
there is at least one change in the procedure itself and it is in the 'road load force' (as a function of speed) that the manufacturer provides to the dyno test to simulate road load (aero, real road rolling resistance etc.).
This is conducted by the manufacturer on the road by coast-down tests that now should be conducted at various speeds up to 50 mph (previously it was up to 70 mph).
Experts say it may influence the fuel economy result of the EPA test.

 

if you look at excel data on EPA site load had been reported not something new. I will check but coast down data also state the procedure used, and they accept both at this point. 50 vs 70 is interesting discussion as one would favour city and other highway. If they reduced speed the easiest way to counter it by pumping up tires.

 

i don't know anything about the new testing parameters, i'm just going by what i have read here. are you claiming to know for sure that a car that tested 30 mpg in 2015, will still be 30 mpg in 2016? i haven't read anyone else saying that.

 

It'd be really nice if there was some standardized testing method that could be quoted, regardless of how wacked out it was, just so there'd be some constant for comparison.

 

agreed.

 

The EPA test cycles aren't changing. Neither is the way the raw results are adjusted for the window sticker.

Sounds like much of the changes are in regard to the rules on the condition of the test vehicle and its equipment, and the pre-test procedures, or that the EPA is going to be stricter about them. It could just be clarification of some of the rules. We've all heard about Hyundai's 'cheating' on the MPG. I used the air quotes because Hyundai's error happened due to a misunderstanding of these current rules, and they weren't fined has fine as if their actions were intentional.

The biggest change is the higher starting speed for the coast down test to determine the road load for the test equipment. This might make a change to the results, but we won't see how much until the data is out for a model that was tested under both procedures.

Any changes will be easier to see in a high fuel efficiency car like the Prius. I expect some, but not enough to get the 4% improvement to 10%.

 

That is the biggest advantage of the NEDC test cycle over the adjusted EPA one. Although far from real world driving but at least based on known parameters without adjusting fomulee and can easily repeated by a third party and good for comparison.

 

The EPA posts the test cycles.
Detailed Test Information

The city and highway ones are the main cycles. The other three are used for adjusting the window sticker. If you don't care for adjustment and whether the posted number is close to real world, then look up the model's CAFE number. That is just the unadjusted city and highway test results.

 

It should improve the precision of the V**2 coefficient but not change the value.

Does anyone have a link to the new EPA testing procedure?

Bob Wilson

 

what is in troll's post above yours?

 

here is a link to raw data and link to the library
Test Car List Data Files | Cars and Light Trucks | US EPA
Basic Search | Document Index System | US EPA

 

All we got is some reports about changes to the rules. I think I summed up all they have said.

 

All @Jeff N could find is this letter to manufacturers