New member, new to Mazdas, couple questions :)

[MP5x2k3]

Dunno. Numbers don't lie though, and yes am resetting the trip meter at fill up every time from a completely full tank and resetting it at fill up. Only thing I can think of that is affecting the.mpg like this is my conservative driving. Who knows, the former owner could have put the taller 4th gear in...dunno. my spec sheet/dealership window sticker does say 5 speed manual transmission with overdrive....that could have some affect on it. But I'm regularly seeing around 34-36 mpg in town and 40+ highway

Looked at the tires again, I'm running hankook option h426 in 195/50-16 on stock wheels. Going to change that out as soon as I can afford new tires for.the 17" lowenhart sniper wheels that my friend just gave me. That'll probably bring mpg down some, but they are going to be my summer wheels anyhow, so no big deal. Looking at 205/40-17

 

[MrGiggles]

Dunno. Numbers don't lie though, and yes am resetting the trip meter at fill up every time from a completely full tank and resetting it at fill up. Only thing I can think of that is affecting the.mpg like this is my conservative driving. Who knows, the former owner could have put the taller 4th gear in...dunno. my spec sheet/dealership window sticker does say 5 speed manual transmission with overdrive....that could have some affect on it. But I'm regularly seeing around 34-36 mpg in town and 40+ highway

Looked at the tires again, I'm running hankook option h426 in 195/50-16 on stock wheels. Going to change that out as soon as I can afford new tires for.the 17" lowenhart sniper wheels that my friend just gave me. That'll probably bring mpg down some, but they are going to be my summer wheels anyhow, so no big deal. Looking at 205/40-17

Larger tires would in theory net you higher MPG on the highway, since you'll have effectively lowered (numerically) your gear ratio. This may be offset by the higher rolling resistance of wider tires and weight, which varies depending on the wheel.

 

[MP5x2k3]

Larger tires would in theory net you higher MPG on the highway, since you'll have effectively lowered (numerically) your gear ratio. This may be offset by the higher rolling resistance of wider tires and weight, which varies depending on the wheel.

Kinda what I was thinking. These Lowenhart wheels are pretty heavy. I need to do the calculations on Miata.net to see how much of a difference its going to make going larger on the wheels/tires. I am planning to get LRR tires though for certain to try and keep my MPG at a respectable number.

Thinking a bit more on my high MPG, one other thing that may be effecting it is that I don't no lift shift. As in, when I shift, I lift my foot off the gas and let the rpms fall, then ease back into it right after I let the clutch out fully.

 

[MP5x2k3]

Larger tires would in theory net you higher MPG on the highway, since you'll have effectively lowered (numerically) your gear ratio. This may be offset by the higher rolling resistance of wider tires and weight, which varies depending on the wheel.

Kinda what I was thinking. These Lowenhart wheels are pretty heavy. I need to do the calculations on Miata.net to see how much of a difference its going to make going larger on the wheels/tires. I am planning to get LRR tires though for certain to try and keep my MPG at a respectable number.

Thinking a bit more on my high MPG, one other thing that may be effecting it is that I don't no lift shift. As in, when I shift, I lift my foot off the gas and let the rpms fall, then ease back into it right after I let the clutch out fully.

 

[MP5x2k3]

Tire Size Comparison

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
195/50-16 3.8in 11.8in 23.7in 74.4in 852 0.0%
205/40-17 3.2in 11.7in 23.5in 73.7in 860 -0.9%
215/40-17 3.4in 11.9in 23.8in 74.7in 848 0.4%
205/45-17 3.6in 12.1in 24.3in 76.2in 831 2.5%
215/45-17 3.8in 12.3in 24.6in 77.3in 819 4.0%

So judging by this chart, if I want to keep my mpg respectable and get a bit better handling, without harshing the ride and throwing my speedo/odo off, I'd be best to go with the 215/40-17?

 

[MP5x2k3]

Well, on further inspection, these wheels may not work after all...

Flipped them over and looked on the back, they are marked 17x8 +45 offset. They aren't lowenhart either, they are Kosei Sniper wheels. Really nice but I think they may be too wide. And at 24 lb each, possibly a bit heavy. Bolt pattern is correct, hub diameter is right, but not sure about the width. From what I read in another thread, 7.5 is about the widest I can go without rubbing spring perches, and they require fenders to be rolled.

Can anyone clarify this for me?

Pic of wheels in question. If I can make them work, they are going on a silver 03 P5

 

[nickthaskater]

Thinking a bit more on my high MPG, one other thing that may be effecting it is that I don't no lift shift. As in, when I shift, I lift my foot off the gas and let the rpms fall, then ease back into it right after I let the clutch out fully.

Is there anyone who doesn't shift like this..?

 

[MP5x2k3]

Is there anyone who doesn't shift like this..?

Is there a reason you're being such a troll?

 

[nickthaskater]

I'm not. I'm asking simple questions and making observations. Sorry that rubs you the wrong way..?

Seriously though, is there anyone who "no lift shifts" on a daily basis if ever in their P5?

 

[MP5x2k3]

Welp, looks like mods have to take a back seat for awhile. Clutch needs replaced asap...while coming uphill around a bend last night at 70 mph on Cruise control, the car lost power and kicked me out of cruise. My bearings are crunchy sounding anyhow, so I suspect the clutch slipped and caused the.cruise to shut off. Seems like it slips mostly when I go around corners and accelerate

Good time for a new one I guess...spec stage 2 and fidanza here I come...now to find the $1400 for parts and labor...