have two sets of wheels, need opinions..

I'd be surprised if those 18x8 wheels will fit, the tires will be expensive unless you buy some may-pop crap, and they gonna be really heavy. go with the 17's

 

racing hart are a good brand with a great reputation
they might well compete, even be less weight that some lesser known brand

that said, you are unlikely to find any 18" 'lightweight'
without knowing exactly what you are dealing with its hard to say what the weights are
but for me, supposition never stands...

I think these are 18", but the car has a few aero mods

 

17's!!

 

are people putting 8" wide wheels on these cars? it would look cool if they fit.

 

generally larger diameter rims comes with wider too
it may be difficult if not impossible for instance to source a 6"
on the inf I have, 18" start at 7.5" wide, and go all the way to 13" wide in the 30lb bracket per rim

 

but that doesn't answer my question. will an 8" wide wheel fit? and then you gotta wonder what is the MPG hit?

 

au contraire
it answers your question entirely

..since there are already Prius cars with 8" wide wheels on them (see previous image),
we can conclude they can indeed be made to fit

....the ''MPG hit'' .... is a new question
and would need to be considered wholly with other available approaches

 

jeez. a simple yes would have been good.

 

I'd have to steal em cause I damn sure couldn't afford em. but the 18" tire to fit an 8" (we were talking bout 8") wheel, its gonna be alot heavier than the 15" tire and have more rolling resistance. gonna be a hit.
anyway I don't think the op's wheels are magnesium.

 

lets be clear here
at no point did I say 'yes'
had you caught up with previous posts half the answer would have been obvious to you

the proviso would have to be that not all similar rims have the same offset, and it is possible that similar looking wheels have offsets that are unsuitable, ie. not fit, -sy. no ...

 

just occasionally you see what are expensive wheels on ebay and the like offered quite cheaply
Racing Hart are in one of those categories where frankly for racing there are better options and racers trade into and out of different tyre rim combos with a higher frequency. truly high-end 18" rims Like Volk CE28n 18x8 come in at 14.7lbs, or less than stock 15''s
plenty of scope there for a heavier 18" diameter road tyre to be lighter than a 17" on a B grade rim, and be stronger to boot

also, you might benefit from a wider range of tyres than is available on the rather more limited 15"
this would be more apparent on 15"-17" variations.
Is it likely there is a lower RR design than 15" dia options? ....its possible...

So in considering these things the trouble is: if our prime considerations are to be based on performance objectives we need to know more of what is what, and in a situation like this where there seems to be little chance of that happening for the present.

or failing all else, as an alternative a quick use of a set of scales might be instructive too....

 

I asked a simple yes or no question: are people putting 8" wide wheels on these cars? the "previous image" says nothing about width, only "I think these are 18". looks like your answer is maybe.

 

Unfortunately for the Prius that is not correct. The tire design and hysterisis characteristics change quite dramatically as you do up in diameter and thus radically affect fuel economy. I've tried a 17" combo that weighed only 5 more than my 15" combo and mpg still dropped between 4-6mpg depending on what tires I ran. I later switched from the 16lb 17" wheels to 24lb 17" wheels and fuel economy was too close to discern a difference. Once rolling, weight has very little affect on FE in this case. In much stop and go traffic the effect will be larger, however. I believe this is why Toyota didn't spend the extra money to make the OE 17" wheels lighter. Those things are tanks but with the special OE tires they still achieve good FE.

Besides, unless you spend a grip of cash on ultralight wheels you'll never overcome the increased weight because the larger diameter tires weigh significantly more than the OE 15" tires.

 

so bigger diameter tyres will always weigh more than the standard fit
and that costs you MPG...

or does it
Tire Weight database


I think theres always been some resistance to changing anything on a prius in this place,
and a number of myths stand that ought not

so what have we learned?

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you can get larger wheels that are lighter than stock
tyre weights need not be inordinately different, might even be lighter but data is limited
and I would add narrow tyres can be pushed onto wider rims, gone is the notion of more friction


this is what that looks like, .......BFG's on Enkei RPF1 rims