I've been using MRT (Modis Reprojectin tool) to extract EVI bands into a geotiff with geographic coordinates (epsg4326). I did not specify an output resolution to MRT. The output from MRT had a spatial resolution of 0.002543280392921 degrees.
Recently I tried using GDAL to extract EVI bands. First I used gdal_translate to extract the EVI band in SIN. That gets me a image with 231.65m resolution (native MODIS resolution - OK). But when I use gdalwarp to convert the image to epsg:4326, the output resolution is 0.001682583113332 degrees! (again, I did not specify the output resolution in gdalwarp). If I convert to UTM, it gives me a resolution of 179.7m.
Shouldn't gdalwarp give me the same resolution obtained from MRT?