The fuel tank of the RX-8 is 15.8 gallons. I take long trips, and I know that after I get possession of my "8", I will be taking more such trips.

However, I have a problem in that the fuel tank of 15.8 gallons is somewhat too small. I would prefer a larger tank, one that has perhaps a 20 gallon capacity.

I hope there would be a larger tank option, or perhaps that there would be an aftermarket solution . . . but I don't think so, huh?

 

i seriously seriously doubt there'd be an option for a larger tank or 2nd tank =p this isn't a dualie ya know. besides 15 gallons is plenty, i take long trips in my truck right now and it holds 13 gallons while getting 22mpg or so. if mazda's figures are correct, 15.x gallons at 30mpg highway should do you just fine don't you think?

 

Dredging up this old thread because it's something relevant for me.

The overall range per tank of the Rx-8 is something that's been bothering me lately.

Obviously, we now know the Rx-8 isn't going to get 30 mpg on a highway. At a mythical 25 mpg, the Rx-8 would be looking at 400 miles per bone dry tank. At a fairly reachable 20 mpg, we're probably talking about 300 miles with 20 miles to find a gas station. At 16 mpg, we're now looking around 240.

It's somewhat arbitrary but I view 400 miles per tank as a comfort area for me with regards to how often I'd need to fill a tank. Remember, the Rx-8 is supposed to be kinda practical (hey, Mazda's making it an advertising point even) and the range is an element of that for me.

The 350z/G35 have somewhat comparable experienced mpg numbers (from a few threads I've read on nissan boards). But they also have 20 gallon tanks. 20 gals on an Rx-8 would put it right around my comfort level of 400 miles per tank.

So what design decisions might limit having a larger tank in an Rx-8? The weight would go up some ( 4 more gals of gas at minimum). Maybe there's not enough room in the chassis to fit this extra space? Basically, is it totally out of line to "request" mazda increase the tank size in a 2005 model?

 

I think they already see this as a problem in the spec's. list.

btw, a month or two back, this topic was discussed in a much larger thread. In there, one of us was saying he ran out of gas & 15.3 was the number to fill it. 1/2 gal not reaching the pickup?

"How many miles out of a tank?"

 

For 2005? Yes, it's too late - I'd bet the 2005 specs are locked in and handed off to suppliers a while ago. But - have you looked at where the fuel tank is? In Mazda's marketing material (see the "Press Kit" thread), there are cutaway drawings showing how the fuel tank is a saddle-bag design that is located under the rear seat and straddles the driveshaft tunnel. There doesn't appear to be much room at all to increase the tank dimensions, certainly not 4 gallons worth.

Regards,
Gordon

 

Comfortable range for me is about 225 miles, meaning I'm getting about 18mpg and filling up after using about 12 gallons. I agree that extending the range would be very nice, but for God's sake, don't touch the trunk or the back seat!

 

my needle was at E and i got 236 on 13.8 gallons, and I was afraid i wasnt going to get to the gas station soon enough. Whats worse is my driving is about 90-95% highway to and from work. I was hoping for 22 or so, not the sub 17 im getting now.

 

I have to say that in a car that is balanced 50/50 you have to take time to plan out your fuel tank. Throwing on a larger capacity tank (saying it would fit) would also throw off the balance. My BMW had a 16 gallon tank and they wouldn't change it for that reason. My battery was even in the trunk of the car for balancing purposes. I don't think that Mazda would risk upsetting those of us who enjoy the balance for those who aren't interested in stopping at gas stations. Anyway why wouldn't you want to stop and show off your car?